Battery-powered stand-alone motor unit

ABSTRACT

A stand-alone motor unit for use with a piece of power equipment includes a housing and a flange coupled to the housing on a first side thereof. A plurality of apertures through the flange defines a first bolt pattern that matches an identical, second bolt pattern defined in the piece of power equipment. An electric motor has a power output of at least about 2760 W. The motor includes a stator having a nominal outer diameter of up to about 80 mm and a rotor supported for rotation within the stator. A power take-off shaft receives torque from the rotor and protrudes from one of the flange or a second side of the housing. A controller is positioned within the housing and electrically connected to the motor. A battery pack for powering the motor has battery cells having a nominal voltage of up to about 80 V.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to co-pending U.S. Provisional PatentApplication No. 62/837,422 filed on Apr. 23, 2019, U.S. ProvisionalPatent Application No. 62/813,920 filed on Mar. 5, 2019, U.S.Provisional Patent Application No. 62/774,946 filed on Dec. 4, 2018, andU.S. Provisional Patent Application No. 62/723,540 filed on Aug. 28,2018, the entire contents of all of which are incorporated herein byreference.

FIELD OF THE INVENTION

The present invention relates to motor units, and more particularly tomotor units for use with power equipment.

BACKGROUND OF THE INVENTION

Small, single or multi-cylinder gasoline engines can be mounted to powerequipment to drive the equipment with a power take-off shaft.

SUMMARY OF THE INVENTION

The present invention provides, in one aspect, a stand-alone motor unitfor use with a piece of power equipment. The motor unit comprises ahousing and a flange coupled to the housing on a first side thereof. Themotor unit also comprises a plurality of apertures through the flangedefining a first bolt pattern that matches an identical, second boltpattern defined in the piece of power equipment. The motor unit alsocomprises an electric motor located within the housing and having apower output of at least about 2760 W and a nominal diameter of up toabout 80 mm. The motor includes a stator and a rotor supported forrotation relative to the stator. The motor unit further comprises apower take-off shaft receiving torque from the rotor and protruding fromone of the flange or a second side of the housing adjacent the firstside. The motor unit also comprises a controller positioned within thehousing and electrically connected to the motor. The motor unit alsocomprises a battery pack including a pack housing, battery cellssupported by the pack housing, and a first terminal electricallyconnected to the battery cells. The battery cells are electricallyconnected and have a nominal voltage of up to about 80 V. The motor unitfurther comprises a battery receptacle coupled to the housing andincluding a second terminal electrically connected to the controller andengageable with the first terminal to transfer current between thebattery pack and the motor.

The present invention provides, in another aspect, a stand-alone motorunit for use with a piece of power equipment. The motor unit comprises ahousing having a first side, a second side adjacent the first side, anda third side opposite the second side. The first side defines a planecontaining orthogonal X and Y axes that intersect at an origin. Themotor unit further comprises a flange coupled to the housing on thefirst side, an electric motor arranged within the housing, a batterypack for providing power to the motor, and a power take-off shaftreceiving torque from the motor and protruding from the second side ofthe housing. The power take-off shaft extends parallel with the Y-axisand has an end. The motor unit further comprises a plurality ofapertures through the flange defining a first bolt pattern that matchesan identical, second bolt pattern defined in the piece of powerequipment. The plurality of apertures includes a first hole, a secondhole, and a first slot including a first semi-circular portion having afirst radius, a second semi-circular portion having a second radius, anda straight portion that connects the first and second semi-circularportions. The plurality of apertures also includes and a second slotincluding a third semi-circular portion having a third radius, a fourthsemi-circular portion having a fourth radius, and a straight portionthat connects the third and fourth semi-circular portions.

The present invention provides, in yet another aspect, a stand-alonemotor unit for use with a piece of power equipment. The motor unitcomprises a housing having a first side and a second side adjacent thefirst side, a flange coupled to the first side of the housing, and aplurality of apertures through the flange defining a first bolt patternthat matches an identical, second bolt pattern defined in the piece ofpower equipment. The motor unit further comprises an electric motorarranged in the housing and including an output shaft, a battery packfor providing power to the motor, a power take-off shaft protruding fromthe second side of the housing, and a gear train for transferring torquefrom the output shaft of the motor to the power take-off shaft. The geartrain includes a first gear set with a first reduction stage. The firstgear set receives torque from the output shaft of the motor. The geartrain also includes a second gear set with a second reduction stage. Thesecond gear set transfers torque from the first gear set to the powertake-off shaft.

The present invention provides, in yet another aspect, a stand-alonemotor unit for use with a piece of power equipment. The motor unitcomprises a housing, a flange coupled to the housing on a first sidethereof, and a plurality of apertures through the flange defining afirst bolt pattern that matches an identical, second bolt patterndefined in the piece of power equipment. The motor unit furthercomprises an electric motor located within the housing and a powertake-off shaft receiving torque from the motor and protruding from oneof the flange or a second side of the housing adjacent the first side.The motor unit further comprises a battery pack for providing power tothe motor, an adapter plate adjacent the motor, and a first gearbox witha first gear train having a first reduction ratio. The first gearbox isconfigured to be removably attached to the adapter plate, such that whenthe first gearbox is attached to the adapter plate, the first gear trainis configured to transfer torque from the motor to the power take-offshaft. The motor unit further comprises a second gearbox with a secondgear train having a second reduction ratio that is different from thefirst reduction ratio. The second gearbox is configured to be removablyattached to the adapter plate, such that when the second gearbox isattached to the adapter plate, the second gear train is configured totransfer torque from the motor to the power take-off shaft.

The present invention provides, in yet another aspect, a stand-alonemotor unit for use with a piece of power equipment. The motor unitcomprises a housing, a flange coupled to the housing on a first sidethereof and a plurality of apertures through the flange defining a firstbolt pattern that matches an identical, second bolt pattern defined inthe piece of power equipment. The motor unit further comprises anelectric motor located within the housing and a power take-off shaftreceiving torque from the motor and protruding from one of the flange ora second side of the housing adjacent the first side. The motor unitfurther comprises a battery pack for providing power to the motor, agearbox with a first slot, and a first gear stage cartridge removablyreceivable into the first slot, such that when the first gear stagecartridge is received in the first slot, the first gear stage cartridgetransfers torque from the motor to the power take-off shaft at a firstreduction ratio. The motor unit further comprises a second gear stagecartridge removably receivable into the first slot, such that when thesecond gear stage cartridge is received in the first slot, the secondgear stage cartridge transfers torque from the motor to the powertake-off shaft at a second reduction ratio that is different from thefirst reduction ratio.

The present invention provides, in yet another aspect, a stand-alonemotor unit for use with a piece of power equipment. The motor unitcomprises a housing, a flange coupled to the housing on a first sidethereof, and a plurality of apertures through the flange defining afirst bolt pattern that matches an identical, second bolt patterndefined in the piece of power equipment. The motor unit furthercomprises an electric motor located within the housing, a battery packfor providing power to the motor, and a gearbox including a gear trainfor transferring torque from the motor. The gear train includes aterminal shaft section. The motor unit further comprises a first shaftsubassembly including a first power take-off shaft and a mating portionconfigured to mate with the terminal shaft section, such that when themating portion of the first shaft subassembly is mated with the terminalshaft section, the gear train is configured to transfer torque from themotor to the first power take-off shaft. The motor unit furthercomprises a second shaft subassembly including a second power take-offshaft that is different from the first power take-off shaft and themating portion configured to mate with the terminal shaft section, suchthat when the mating portion of the second shaft subassembly is matedwith the terminal shaft section, the gear train is configured totransfer torque from the motor to the second power take-off shaft.

The present invention provides, in yet another aspect, a stand-alonemotor unit for use with a piece of power equipment. The motor unitcomprises a housing having a first side, a second side adjacent thefirst side, and an interior. The motor unit further comprises a flangecoupled to the first side of the housing and a plurality of aperturesthrough the flange defining a first bolt pattern that matches anidentical, second bolt pattern defined in the piece of power equipment.The motor unit further comprises an electric motor located within theinterior of the housing, a battery pack for providing power to themotor, and a power take-off shaft receiving torque from the motor andprotruding from one of the flange or the second side of the housing. Themotor unit further comprises a plurality of doors arranged on thehousing. Each of the doors is configured to be selectively opened andclosed to selectively allow a cooling airflow to enter the interior ofthe housing and cool the motor.

The present invention provides, in yet another aspect, a stand-alonemotor unit for use with a piece of power equipment. The motor unitcomprises a housing having a first side and a second side adjacent thefirst side, a flange coupled to the first side of the housing, and aplurality of apertures through the flange defining a first bolt patternthat matches an identical, second bolt pattern defined in the piece ofpower equipment. The motor unit further comprises an electric motorarranged in the housing, a battery pack for providing power to themotor, and a gearbox arranged on the second side of the housing. Thegearbox supports at least a portion of a gear train that receives torquefrom the motor. The motor unit further comprises a shaft subassemblyremovably coupled to the gearbox. The shaft subassembly includes a powertake-off shaft and a first gear coupled to the power take-off shaft,such that the power take-off shaft is rotatable with the first gear.When the shaft subassembly is coupled to the gearbox, the first gearmates with the portion of the gear train in the gearbox, such that thefirst gear is the final gear of the gear train and the gear train isconfigured to transfer torque from the motor to the power take-offshaft.

The present invention provides, in yet another aspect, a stand-alonemotor unit for use with a piece of power equipment. The motor unitcomprises a housing having a first side, a second side adjacent thefirst side, and a third side opposite the second side. The motor unitfurther comprises a flange coupled to the first side of the housing anda plurality of apertures through the flange defining a first boltpattern that matches an identical, second bolt pattern defined in thepiece of power equipment. The motor unit further comprises an electricmotor arranged in the housing, a battery pack for providing power to themotor, and a first power take off shaft configured to receive torquefrom the motor and protruding from the second side of the housing. Themotor unit further comprises a second power take-off shaft configured toreceive torque from the motor and protruding from the third side of thehousing.

The present invention provides, in yet another aspect, a stand-alonemotor unit for use with a piece of power equipment. The motor unitcomprises a housing having a first side and a second side adjacent thefirst side. The motor unit further comprises a flange coupled to thefirst side of the housing and a plurality of apertures through theflange defining a first bolt pattern that matches an identical, secondbolt pattern defined in the piece of power equipment. The motor unitfurther comprises an electric motor arranged in the housing, a batterypack for providing power to the motor, and a power take-off shaftconfigured to receive torque from the motor and protruding from thesecond side of the housing. The power take-off shaft defines arotational axis. The housing is moveable with respect to the flange,such that a position of the power take-off shaft can be adjusted withrespect to the flange.

The present invention provides, in yet another aspect, a stand-alonemotor unit for use with a piece of power equipment. The motor unitcomprises a housing having a first side and a second side adjacent thefirst side. The motor unit further comprises a flange coupled to thefirst side of the housing and a plurality of apertures through theflange defining a first bolt pattern that matches an identical, secondbolt pattern defined in the piece of power equipment. The motor unitfurther comprises an electric motor arranged in the housing, a batterypack for providing power to the motor, and a power take-off shaftconfigured to receive torque from the motor and protruding from thesecond side of the housing. The motor unit further comprises a sensorport on the housing that is configured to electronically connect to asensor for use with the piece of power equipment.

The present invention provides, in yet another aspect, a stand-alonemotor unit for use with a piece of power equipment. The motor unitcomprises a housing having a first side and a second side adjacent thefirst side. The motor unit further comprises a flange coupled to thefirst side of the housing and a plurality of apertures through theflange defining a first bolt pattern that matches an identical, secondbolt pattern defined in the piece of power equipment. The motor unitfurther comprises an electric motor arranged in the housing, a batterypack for providing power to the motor, and a power take-off shaftconfigured to receive torque from the motor and protruding one of thefirst side or the second side of the housing. The motor unit furthercomprises an AC power output on the housing configured to receive an ACpower cord of a power tool, such that power from the battery can betransmitted to the power tool.

The present invention provides, in yet another aspect, a stand-alonemotor unit for use with a piece of power equipment. The motor unitcomprises a housing having a first side and a second side adjacent thefirst side. The motor unit further comprises a flange coupled to thefirst side of the housing and a plurality of apertures through theflange defining a first bolt pattern that matches an identical, secondbolt pattern defined in the piece of power equipment. The motor unitfurther comprises an electric motor arranged in the housing, a batterypack for providing power to the motor, and a power take-off shaftconfigured to receive torque from the motor and protruding one of thefirst side or the second side of the housing. The motor unit furthercomprises a DC power output on the housing configured to receive a DCpower cord of an accessory, such that power from the battery can betransmitted to the accessory.

The present invention provides, in yet another aspect, a stand-alonemotor unit for use with a piece of power equipment. The motor unitcomprises a housing having a first side and a second side adjacent thefirst side. The motor unit further comprises a flange coupled to thefirst side of the housing and a plurality of apertures through theflange defining a first bolt pattern that matches an identical, secondbolt pattern defined in the piece of power equipment. The motor unitfurther comprises an electric motor arranged in the housing, a batterypack for providing power to the motor, and a power take-off shaftconfigured to receive torque from the motor and protruding one of thefirst side or the second side of the housing. The motor unit furthercomprises an inlet in the housing for receipt of pressurized air forcleaning an interior of the housing or cooling the motor.

The present invention provides, in yet another aspect, a trash pumpsystem comprising a frame and a pump supported by the frame. The pumpincludes an inlet, an outlet, and a pump mechanism configured to draw afluid into the inlet and discharge the fluid from the outlet. The pumpalso includes a first sensor configured to detect the amount of a fluidmoving through the inlet or the outlet. The trash pump system furthercomprises a stand-alone motor unit coupled to the pump. The motor unitincludes a housing having a first side and a second side adjacent thefirst side, a flange coupled to the first side of the housing, and aplurality of apertures through the flange defining a first bolt patternthat matches an identical, second bolt pattern defined in the pump. Themotor unit also includes an electric motor arranged in the housing, abattery pack for providing power to the motor, an electronic processorconfigured to control the motor, and a power take-off shaft configuredto receive torque from the motor and protruding from one of the firstside or the second side of the housing and into the pump, such that thepower take-off shaft can drive the pump mechanism. The electronicprocessor is configured to determine whether the fluid is at or above athreshold level via the first sensor in the pump. In response todetecting that the amount of fluid is below the threshold level, theelectronic processor stops the motor.

The present invention provides, in yet another aspect, a jetter systemcomprising a frame, a plurality of wheels on the frame, a handle on theframe, a hose reel on the frame, and a pump supported by the frame. Thepump includes an inlet, an inlet line configured to be coupled to asource of fluid, an outlet, an outline line extending from the outlet,and a pump mechanism configured to draw the fluid from the source offluid through the inlet line, into the inlet, and discharge the fluidfrom the outlet. The pump also includes a fluid level sensor configuredto detect a level of fluid in the pump. The jetter system furthercomprises a jetter nozzle including back jets and front jets and a hosearranged on the hose reel and fluidly coupling the outlet line of thepump to the jetter nozzle. The jetter system further comprises astand-alone motor unit coupled to the pump. The motor unit includes ahousing having a first side and a second side adjacent the first side, aflange coupled to the first side of the housing, and a plurality ofapertures through the flange defining a first bolt pattern that matchesan identical, second bolt pattern defined in the pump. The motor unitalso includes an electric motor arranged in the housing, a battery packfor providing power to the motor, an electronic processor configured tocontrol the motor, and a power take-off shaft configured to receivetorque from the motor and protruding from one of the first side or thesecond side of the housing and into the pump, such that the powertake-off shaft can drive the pump mechanism. The electronic processor isconfigured to determine whether there is an adequate level of fluidavailable in the pump based on the level of fluid detected by the fluidlevel sensor.

The present invention provides, in yet another aspect, a compactorsystem comprising a frame including a handle, a vibrating platesupported by the frame, a vibration mechanism configured to drive thevibrating plate, a valve for dispensing a fluid, and a stand-alone motorunit coupled to the vibration mechanism. The motor unit includes ahousing having a first side and a second side adjacent the first side, aflange coupled to the first side of the housing, and a plurality ofapertures through the flange defining a first bolt pattern that matchesan identical, second bolt pattern defined in the vibration mechanism.The motor unit also includes an electric motor arranged in the housing,a battery pack for providing power to the motor, an electronic processorconfigured to control the motor, and a power take-off shaft configuredto receive torque from the motor and protruding from one of the firstside or the second side of the housing and into the vibration mechanism,such that the power take-off shaft can drive the vibration mechanism.The electronic processor is configured to control the valve to adjust aflow rate of the fluid.

The present invention provides, in yet another aspect, a rammer systemcomprising a body, a handle extending from the body, a vibrating platesupported by the body, a vibration mechanism configured to drive thevibrating plate, a sensor configured to detect a frequency of thevibrating plate, and stand-alone motor unit coupled to the body. Thestand-alone motor unit includes a housing having a first side and asecond side adjacent the first side, a flange coupled to the first sideof the housing, and a plurality of apertures through the flange defininga first bolt pattern that matches an identical, second bolt patterndefined in the body. The motor unit also includes an electric motorarranged in the housing, a battery pack for providing power to themotor, an electronic processor configured to control the motor, and apower take-off shaft configured to receive torque from the motor andprotruding from one of the first side or the second side of the housingand into the vibration mechanism, such that the power take-off shaft candrive the vibration mechanism. In response to the sensor detecting thatthe frequency of the vibrating plate is in a predetermined range, theelectronic processor reduces the speed of the electric motor.

The present invention provides, in yet another aspect, a stand-alonemotor unit for use with a piece of power equipment. The motor unitcomprises a housing, a flange coupled to the housing on a first sidethereof, and a plurality of apertures through the flange defining afirst bolt pattern that matches an identical, second bolt patterndefined in the piece of power equipment. The motor unit furthercomprises an electric motor located within the housing. The electricmotor includes a stator and a rotor supported for rotation within thestator. The motor unit further comprises a power take-off shaftreceiving torque from the rotor and protruding from one of the flange ora second side of the housing adjacent the first side. The motor unitfurther comprises a current sensor configured to detect a currentflowing to the motor and a controller positioned within the housing andelectrically connected to the motor and the current sensor. Thecontroller is configured to measure, using the current sensor, a motorcurrent, measure a motor speed, determine a point on a motor power curvecorresponding to the measured motor current and the measured motorspeed, determine whether the stand-alone motor unit is operating in ano-load condition for a pre-determined period of time based on the pointon the motor power curve, in response to determining that thestand-alone motor unit is operating in the no-load condition for apre-determined period of time, reduce the motor speed of the motor to ano-load speed, and in response to determining that the stand-alone motorunit is not operating in the no-load condition for a pre-determinedperiod of time, operating the motor at a loaded speed that is greaterthan the no-load speed. The motor unit further comprises a batteryreceptacle coupled to the housing and configured to receive a batterypack and transfer current between the battery pack and the motor.

The present invention provides, in yet another aspect, a stand-alonemotor unit for use with a piece of power equipment. The motor unitcomprises a housing, a flange coupled to the housing on a first sidethereof, and a plurality of apertures through the flange defining afirst bolt pattern that matches an identical, second bolt patterndefined in the piece of power equipment. The motor unit furthercomprises an electric motor located within the housing. The electricmotor includes a stator and a rotor supported for rotation relative tothe stator. The motor unit further comprises a power take-off shaftreceiving torque from the rotor and protruding from one of the flange ora second side of the housing adjacent the first side. The motor unitfurther comprises a current sensor configured to detect a currentflowing to the motor, a power switching network, a user input device forreceiving a user input, and a controller positioned within the housingand electrically connected to the motor through the power switchingnetwork, and electrically connected to the current sensor and the userinput device. The controller is configured to control the powerswitching network to provide power to the motor in response todetermining that the user input device has been actuated, detect, usingthe current sensor, a current level of the motor, compare the currentlevel to a bog-down current threshold, and in response to determiningthat the current level is greater than the bog-down current threshold,control the power switching network to simulate bog-down. The motor unitfurther comprises a battery receptacle coupled to the housing andconfigured to receive a battery pack and transfer current between thebattery pack and the motor.

The present invention provides, in yet another aspect, a stand-alonemotor unit for use with a piece of power equipment. The motor unitcomprises a housing, a flange coupled to the housing on a first sidethereof, and a plurality of apertures through the flange defining afirst bolt pattern that matches an identical, second bolt patterndefined in the piece of power equipment. The motor unit furthercomprises an electric motor located within the housing. The electricmotor includes a stator and a rotor supported for rotation within thestator. The motor unit further comprises a power take-off shaftreceiving torque from the rotor and protruding from one of the flange ora second side of the housing adjacent the first side. The motor unitfurther comprises a transceiver, a battery receptacle coupled to thehousing and configured to receive a battery pack and transfer currentbetween the battery pack and the motor, and a controller positionedwithin the housing and electrically connected to the motor and thetransceiver. The controller is configured to receive, via thetransceiver, a load command from the piece of power equipment, determinea load limit of the battery pack, determine whether the load commandexceeds the load limit, in response to determining that the load commanddoes not exceed the load limit, perform normal operation of thestand-alone motor unit, and in response to determining that the loadcommand exceeds the load limit perform limited operation of thestand-alone motor unit.

Other features and aspects of the invention will become apparent byconsideration of the following detailed description and accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a stand-alone motor unit in accordancewith an embodiment of the invention.

FIG. 2 is a plan view of the stand-alone motor unit of FIG. 1.

FIG. 3 is a schematic view of the stand-alone motor unit of FIG. 1.

FIG. 4 is a perspective view of a battery pack of the stand-alone motorunit of FIG. 1.

FIG. 5 is a cross-sectional view of the battery pack of FIG. 4.

FIG. 6 is a cross-sectional view of a battery receptacle of thestand-alone motor unit of FIG. 1.

FIG. 7 is a cross-sectional view of a motor of the stand-alone motorunit of FIG. 1.

FIG. 8 is a schematic view of a motor of the stand-alone motor unit ofFIG. 1.

FIG. 9 is a schematic view of a motor, a gear train, and a powertake-off shaft of the stand-alone motor unit of FIG. 1.

FIG. 10 is a schematic view of a motor, a gear train, and a powertake-off shaft of the stand-alone motor unit of FIG. 1 in a firstconfiguration.

FIG. 11 is a schematic view of a motor, a gear train, and a powertake-off shaft of the stand-alone motor unit of FIG. 1 in a secondconfiguration.

FIG. 12 is a schematic view of a motor, a gear train, and a powertake-off shaft of the stand-alone motor unit of FIG. 1 in a thirdconfiguration.

FIG. 13 is a plan view of a stand-alone motor unit in accordance withanother embodiment of the invention.

FIG. 14 is a plan view of the stand-alone motor unit of FIG. 13.

FIG. 15 is a schematic view of a first side of the stand-alone motorunit of FIG. 1.

FIG. 16 is a schematic view of a second side of the stand-alone motorunit of FIG. 1.

FIG. 17 is an enlarged plan view of a first slot of the stand-alonemotor unit of FIG. 1.

FIG. 18 is an enlarged plan view of a second slot of the stand-alonemotor unit of FIG. 1.

FIG. 19 is a schematic view of a motor, a gear train, and a powertake-off shaft of the stand-alone motor unit of FIG. 1 in a fourthconfiguration.

FIG. 20 is a block diagram of the stand-alone motor unit of FIG. 1.

FIG. 21 is a block diagram of a user equipment communicating with themotor unit of FIG. 1.

FIG. 22 is a flowchart of a method for no-load operation of the motorunit of FIG. 1.

FIG. 23 is a graphical illustration of power savings offered by themotor unit of FIG. 1 implementing the method of FIG. 22.

FIG. 24 is a flowchart of a method for providing simulated bog-downoperation of the motor unit of FIG. 1 that is similar to actual bog-downexperienced by gas engines.

FIG. 25 is a schematic diagram of the motor unit of FIG. 1 that showshow an electronic processor of the motor unit implements the methods ofFIG. 24.

FIG. 26 is a schematic diagram of the motor unit of FIG. 1 that showshow an electronic processor of the motor unit implements the method ofFIG. 24 with user customization.

FIG. 27 is a flowchart of a method for checking compatibility of themotor unit of FIG. 1 for a user-selected application.

FIG. 28 is a perspective view of a pump system including a stand-alonemotor unit of FIG. 42.

FIG. 29 is a perspective view of a jetter including the stand-alonemotor unit of FIG. 42.

FIG. 30 is a perspective view of a compactor including the stand-alonemotor unit of FIG. 42.

FIG. 31 is a schematic view of a vibration mechanism of the compactor ofFIG. 30.

FIG. 32 is a perspective view of a rammer including the stand-alonemotor unit of FIG. 42.

FIG. 33 is a schematic view of coupling arrangement for a gear train ofthe motor unit of FIG. 42 and a female shaft subassembly.

FIG. 34 is a schematic view of coupling arrangement for a gear train ofthe motor unit of FIG. 42 and a male shaft subassembly.

FIG. 35 is a perspective view of a half-circle shaft with female borecoupling arrangement for the coupling mechanism of FIG. 33 or 34.

FIG. 36 is a perspective view of a tongue and groove couplingarrangement for the coupling mechanism of FIG. 33 or 34.

FIG. 37 is a perspective view of a double D coupling arrangement for thecoupling mechanism of FIG. 33 or 34.

FIG. 38 is a perspective view of a serrated coupling arrangement for thecoupling mechanism of FIG. 33 or 34.

FIG. 39 is a perspective view of a peg coupling arrangement for thecoupling mechanism of FIG. 33 or 34.

FIG. 40 is a perspective view of a female collar with radial fastenerscoupling arrangement for the coupling mechanism of FIG. 33 or 34.

FIG. 41 is a cross-sectional view of a coupling arrangement for a geartrain of the motor unit of FIG. 1 and a male shaft subassembly.

FIG. 42 is a perspective view of a motor unit according to anotherembodiment of the invention.

FIG. 42a is another perspective view of the motor unit of FIG. 42

FIG. 43 is a cross-sectional view of a coupling arrangement for a geartrain of the motor unit of FIG. 1 and a shaft subassembly.

FIG. 44 is a cross-sectional view of a coupling arrangement for a geartrain of the motor unit of FIG. 1 and a shaft subassembly.

FIG. 45 is a schematic view of a mounting arrangement for a motor and agearbox of the motor unit of FIG. 42.

FIG. 46 is a schematic view of a gearbox and geartrain of the motor unitof FIG. 42.

FIG. 47 is a perspective view of an arrangement of a motor and ageartrain of the motor unit of FIG. 42.

FIG. 48 is a perspective view of a motor unit according to anotherembodiment of the invention.

FIG. 49 is a schematic view of a coupling arrangement between a powertake-off shaft of the motor unit of FIG. 42 and a tool input shaft.

FIG. 50 is a schematic view of a gearbox of the motor unit of FIG. 42.

FIG. 51 is a perspective view of the battery of FIG. 4 in a cover.

FIG. 52 is a perspective view of a battery for the motor unit of FIG.42.

FIG. 53 is a plan view of a remote control for use with the motor unitof FIG. 42.

Before any embodiments of the invention are explained in detail, it isto be understood that the invention is not limited in its application tothe details of construction and the arrangement of components set forthin the following description or illustrated in the following drawings.The invention is capable of other embodiments and of being practiced orof being carried out in various ways. Also, it is to be understood thatthe phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting.

DETAILED DESCRIPTION

As shown in FIGS. 1, 2, 14 and 15, a stand-alone motor unit 10 for usewith a piece of power equipment includes a housing 14 with a first side18, a second side 22 adjacent the first side 18, a third side 26opposite the second side 22, a fourth side 28 opposite the first side18, a fifth side 30 extending between the second and third sides 22, 26,and a sixth side 32 opposite the fifth side 30. The motor unit 10 alsoincludes a flange 34 coupled to the housing 14 on the first side 18, anelectric motor 36 located within the housing 14, and a power take-offshaft 38 that protrudes from the second side 22 and receives torque fromthe motor 36. As explained in further detail below, in some embodiments,the power take-off shaft 38 protrudes from the first side 18 and fromthe flange 34. As shown in FIGS. 3 and 16, the motor unit 10 alsoincludes control electronics 42 positioned within the housing 14 andincluding wiring and a controller 46 that is electrically connected tothe motor 36. In some embodiments, the control electronics 42 has avolume of up to about 820 mm³. In some embodiments, the controlelectronics 42 has a weight of up to about 830 g. FIGS. 42 and 42 aillustrate another embodiment of the motor unit 10, described in greaterdetail below.

As shown in FIGS. 1-6, the motor unit 10 also includes a battery pack 50that is removably received in a battery receptacle 54 in the housing 14to transfer current from the battery pack 50 to the motor 36 via thecontrol electronics 42. With reference to FIGS. 4-6, the battery pack 50includes a battery pack housing 58 with a support portion 62 and a firstterminal 66 that is electrically connected to a plurality of batterycells 68 supported by the pack housing 58. The support portion 62provides a slide-on arrangement with a projection/recess portion 70cooperating with a complementary projection/recess portion 74 (shown inFIG. 6) of the battery receptacle 54. In the embodiment illustrated inFIGS. 4-6, the projection/recess portion 70 of the battery pack 50 is aguide rail and the projection/recess portion 74 of the batteryreceptacle 54 is a guide recess. A similar battery pack is described andillustrated in U.S. patent application Ser. No. 16/025,491 filed Jul. 2,2018, the entire content of which is incorporated herein by reference.In some embodiments, the battery cells 68 have a nominal voltage of upto about 80 V. In some embodiments, the battery cells 68 have a nominalvoltage of up to about 120 V. In some embodiments, the battery pack 50has a weight of up to about 6 lb. In some embodiments, each of thebattery cells 68 has a diameter of up to 21 mm and a length of up toabout 71 mm. In some embodiments, the battery pack 50 includes up totwenty battery cells 68. In some embodiments, the battery cells 68 areconnected in series. In some embodiments, the battery cells 68 areoperable to output a sustained operating discharge current of betweenabout 40 A and about 60 A. In some embodiments, each of the batterycells 68 has a capacity of between about 3.0 Ah and about 5.0 Ah.

FIG. 6 illustrates the battery receptacle 54 of the motor unit 10 inaccordance with some embodiments. The battery receptacle 54 includes theprojection/recess 74, a second terminal 78, a latching mechanism 82, anda power disconnect switch 86. The projection/recess 74 cooperates withthe projection/recess 70 of the battery pack 50 to attach the batterypack 50 to the battery receptacle 54 of the motor unit 10. When thebattery pack 50 is attached to the motor unit 10, the second terminal 78and the first terminal 66 are electrically connected to each other. Thelatching mechanism 82 protrudes from a surface of the battery receptacle54 and is configured to engage the battery pack 50 to maintainengagement between the battery pack 50 and the battery receptacle 54.Thus, the battery pack 50 is connectable to and supportable by thebattery receptacle 54 such that the battery pack 50 is supportable bythe housing 14 of the stand-alone motor unit 10. In some embodiments,the battery pack receptacle 54 is arranged on the housing 14 in aposition to create a maximum possible distance of separation between themotor 36 and the battery pack 50, in order to inhibit vibrationtransferred from the motor 36 to the battery pack 50. In someembodiments, elastomeric members are positioned on the battery packreceptacle 54 in order to inhibit vibration transferred from the motor36, via the housing 14, to the battery pack 50.

In other embodiments (not shown), the latching mechanism 82 may bedisposed at various locations (e.g., on a sidewall, an end wall, anupper end wall etc., of the battery receptacle 54) such that thelatching mechanism 82 engages corresponding structure on the batterypack 50 to maintain engagement between the battery pack 50 and thebattery receptacle 54. The latching mechanism 82 includes a pivotableactuator or handle 90 operatively engaging a latch member 94. The latchmember 94 is slidably disposed in a bore 98 of the receptacle 54 and isbiased toward a latching position by a biasing member 102 (e.g., aspring) to protrude through a surface of the battery receptacle 54 andinto a cavity in the battery pack 50.

The latching mechanism also 82 includes the power disconnect switch 86(e.g., a micro-switch) facilitating electrical connecting/disconnectingthe battery pack 50 from the battery receptacle 54 during actuation ofthe handle 90 to withdraw the latch member 94 from the battery pack 50.The power disconnect switch 86 may act to electrically disconnect thebattery pack 50 from the motor unit 10 prior to removal of the batterypack 50 from the battery receptacle 54. The power disconnect switch 86is actuated when the latch member 94 is moved from the latched position(i.e., when the latch member 94 is completely within the cavity of thebattery pack 50) to an intermediate position. The power disconnectswitch 86 is electrically connected to the controller 46 and maygenerate an interrupt to indicate that the battery pack 50 is beingdisconnected from the motor unit 10. When the controller 46 receives theinterrupt, the controller 46 begins a power down operation to safelypower down the control electronics 42 of the motor unit 10. A similarlatching mechanism and disconnect switch is described and illustrated inU.S. patent application Ser. No. 16/025,491, which has been incorporatedherein by reference.

As shown in FIG. 7, the motor 36 includes a motor housing 96 having anouter diameter 97, a stator 98 having a nominal outer diameter 102 of upto about 80 mm, a rotor 102 having an output shaft 106 and supported forrotation within the stator 98, and a fan 108. A similar motor isdescribed and illustrated in U.S. patent application Ser. No.16/025,491, which has been incorporated herein by reference. In someembodiments, the motor 36 is a brushless direct current motor. In someembodiments, the motor 36 has a power output of at least about 2760 W.In some embodiments, the power output of the motor 36 may drop below2760 W during operation. In some embodiments, the fan 108 has a diameter109 that is larger diameter 97 of the motor housing 96. In someembodiments, the motor 36 can be stopped with an electronic clutch (notshown) for quick overload control. In some embodiments, the motor 36 hasa volume of up to about 443,619 mm³. In some embodiments, the motor hasa weight of up to about 4.6 lb. The housing 14 includes an inlet ventand an outlet vent, such that the motor fan 108 pulls air through theinlet vent and along the control electronics 42 to cool the controlelectronics 42, before the air is exhausted through the outlet vent. Inthe embodiment illustrated in FIG. 7, the motor is a 36 is an internalrotor motor, but in other embodiments, the motor 36 can be an outerrotor motor with a nominal outer diameter (i.e. the nominal outerdiameter of the rotor) of up to about 80 mm.

With reference to FIGS. 8-12, the motor 36 can transfer torque to thepower take-off shaft 38 in a variety of configurations. In theembodiment shown in FIG. 8, the output shaft 106 is also the powertake-off shaft 38, such that the motor 36 directly drives the powertake-off shaft 38 without any intermediate gear train. For example, themotor 36 may be a direct drive high pole count motor. As shown in FIG.9, in other embodiments, the motor unit 10 includes a gear train 110that transfers torque from the motor 36 to the power take-off shaft 38.In some embodiments, the gear train 110 can include a mechanical clutch(not shown) to discontinue the transfer of torque from the motor 36 tothe power take-off shaft 38. In the embodiment shown in FIG. 10, thegear train 110 includes a planetary transmission 114 that transferstorque from the output shaft 106 to the power take-off shaft 38, and arotational axis 118 of the output shaft 106 is coaxial with a rotationalaxis 122 of the power take-off shaft 38. In the embodiment shown in FIG.11, the gear train 110 includes a spur gear 126 engaged with the outputshaft 106 of the rotor, such that the rotational axis 118 of the outputshaft 106 is offset from and parallel to the rotational axis 122 of thepower take-off shaft 38. In the embodiment shown in FIG. 12, the geartrain 110 includes a bevel gear 130, such that the rotational axis 118of the output shaft 106 is perpendicular to the rotational axis 122 ofthe power take-off shaft 38. Thus, in the embodiment of FIG. 12, therotational axis 118 of the output shaft 106 intersects the second side22 of the housing 14 and the power take-off shaft 38 protrudes from theflange 34. In other embodiments utilizing a bevel gear, the rotationalaxis 118 of the output shaft 106 is not perpendicular, parallel, orcoaxial to the rotational axis 122 of the power take-off shaft 38, andthe power-take off shaft 38 protrudes from the flange 34.

In the embodiment illustrated in FIG. 19, the gear train 110 includes afirst gear 111 and a second gear 112 making up a first gear set 113 witha first reduction stage 115, and a third gear 116 and a fourth gear 117making up second gear set 119 with a second reduction stage 120. Thefirst gear 111 has a rotational center C1 and is coupled for rotationwith the output shaft 106 of the motor 36. The second and third gears112, 116 have respective rotational centers C2, C3 and are coupled forrotation with a second shaft 121 that is parallel to the output shaft106 and the power take-off shaft 38. The power take-off shaft 38 iscoupled for rotation with the fourth gear 117, which has a rotationalcenter C4. A first center distance CD1 is defined between the rotationalcenters C1 and C2 of the first and second gears 111, 112. A secondcenter distance CD2 is defined between the rotational centers C3 and C4of the third and fourth gears 116, 117. In the illustrated embodiment,the first center distance CD1 is equal to the second center distanceCD2. However, in other embodiments, the first center distance CD1 may bedifferent than the second center distance CD2.

With continued reference to the embodiment illustrated in FIG. 19, thehousing 14 includes a removable faceplate 124 that allows the operatorto remove the faceplate 124 to access the first, second, third, andfourth gears 111, 112, 115, 116 and to slide them off the output shaft106, the second shaft 120 and the power take-off shaft 38. Thus, theoperator may replace the first gear set 113 with a different gear setwith two gears having the same first center distance CD1 between theirrotational centers to change the reduction ratio of the first reductionstage 115. Similarly, the operator may replace the second gear set 119with a different gear set with two gears having the same second centerdistance CD2 between their rotational centers to change the reductionratio of the second reduction stage 120. Thus, the motor unit 10 canimplement a variety of reduction ratios to work with a broad range ofpower equipment, and the removable faceplate 124 makes it easy for anoperator to quickly change these reduction ratios. Also the faceplate124 makes it easy for an operator to change out the power take-off shaft38 to replace it with a custom power take-off shaft for any givenapplication. Also, the faceplate 124 is easily replaced with a differentfaceplate to fit a unique or custom mounting configuration.

In the embodiment shown in FIGS. 13 and 14, the power-take off shaft 38is a first power take-off shaft and the motor unit 10 includes a secondpower take-off shaft 134 that also extends along the rotational axis 122of the first power take off shaft 38. The motor 36 drives the first andsecond power take-off shafts 38, 134 simultaneously, such that the motorunit 10 can be used with, for example, tillers, saws, and snow blowers.

FIGS. 15 and 16 illustrate embodiments of the motor unit 10 in which thepower take-off shaft 38 protrudes through the second side 22 of thehousing 14. As shown in FIG. 15, a plane 138 is defined on the firstside 18 of the housing 14 on which the flange 34 is coupled. The plane138 contains orthogonal X and Y axes that intersect at an origin O. Asshown in FIG. 16, the power take-off shaft 38 extends parallel to theY-axis and as shown in FIG. 15, the power take-off shaft 38 has an end140. The X-axis extends parallel to the second and third sides 22, 26and the Y-axis extends parallel to the fifth and sixth sides 30, 32.

With continued reference to FIG. 15, the flange 34 includes a pluralityof apertures therethrough, including a first hole 142 having a center144, a second hole 146 having a center 148, a first slot 150, and asecond slot 154. The plurality of apertures collectively define a firstbolt pattern that matches an “identical”, second bolt pattern defined ina piece of power equipment to which the motor unit 10 can be mounted.“Identical” does not mean that each of the plurality of aperturesdefining the first bolt pattern identically aligns with each of theplurality of apertures defining the second bolt pattern. In other words,not all of the first hole 142, second hole 146, first slot 150, andsecond slot 154 need align with a corresponding aperture in the secondbolt pattern. Rather, at least two of the first hole 142, second hole146, first slot 150, and second slot 154 will at least partially alignwith two corresponding apertures in the second bolt pattern, such thatat least two fasteners, such as bolts, may be respectively insertedthrough at least two of the at least partially-aligned respectiveapertures of the first and second bolt patterns in order to couple themotor unit 10 to the piece of power equipment. Thus, for the first boltpattern to match an “identical” second bolt pattern, at least twoapertures in the first bolt pattern are configured to at least partiallyalign with two apertures of the second bolt pattern. In the disclosedembodiment, the plurality of apertures defining the first bolt patternincludes four apertures (first hole 142, second hole 146, first slot150, and second slot 154) but in other embodiments, the plurality ofapertures defining the first bolt pattern could include more or fewerapertures.

In some embodiments, the flange 34 may include one or more intermediatemounting members or adapters arranged between the flange 34 itself andthe flange of the piece of power equipment having the second boltpattern, such that the adapter(s) couple the flange 34 to the piece ofpower equipment. In these embodiments, the adapter includes both thesecond bolt pattern and the first bolt pattern, such that the first boltpattern of the flange 34 aligns with the first bolt pattern of theadapter and the second bolt pattern of the adapter aligns with thesecond bolt pattern defined in the piece of power equipment, therebyallowing the flange 34 of the motor unit 10 to be coupled to the pieceof power equipment.

As shown in FIG. 17, the first slot 150 includes a first semi-circularportion 158 having a radius R1, a second semi-circular portion 162having a radius R2, and a straight portion 166 that connects the firstand second semi-circular portions 158, 162. The first semi-circularportion 158 has a center 170 from which radius R1 is defined and thesecond semi-circular portion 162 has a center 174 from which radius R2is defined. The centers 170, 174 can define points where a bolt isinserted through the first slot 150 when the first slot 150 is alignedwith a corresponding aperture in the second bolt pattern in the piece ofpower equipment, but the bolt may also be inserted anywhere along thestraight portion 166.

As also shown in FIG. 18, the second slot 154 includes a firstsemi-circular portion 178 having a radius R3, a second semi-circularportion 182 having a radius R4, and a straight portion 186 that connectsthe first and second semi-circular portions 178, 182. The firstsemi-circular portion 178 has a center 190 from which radius R3 isdefined and the second semi-circular portion 182 has a center 194 fromwhich radius R4 is defined. The centers 170, 174 can define points wherea bolt is inserted through the second slot 154 when the second slot 154is aligned with a corresponding aperture in the second bolt pattern inthe piece of power equipment, but the bolt may also be inserted anywherealong the straight portion 186. In the embodiment illustrated in FIGS.15 and 17, R1, R2, R3, and R4 are all equal, but in other embodiments,one or more of the radii R1, R2, R3, R4 may be different from oneanother.

With reference again to FIG. 15, Table 1 below lists the distances ofvarious components and reference points with respect to the X-axis andthe Y-axis.

TABLE 1 Distance from Distance from X-axis Y-axis Center 144 of firsthole 142 E G Center 148 of second hole 146 E H Center 170 of firstsemi-circular C G portion 158 of first slot 150 Center 174 of secondsemi-circular D G portion 162 of first slot 150 Center 190 of firstsemi-circular C H portion 178 of second slot 154 Center 194 of secondsemi-circular D H portion 182 of second slot 154 Second side 22 ofhousing 14 A Perpendicular to Y-axis Third side 26 of housing 14 BPerpendicular to Y-axis End 140 of power take-off shaft 38 FPerpendicular to Y-axis Fifth side 30 of housing 14 Perpendicular I toX-axis Sixth side 32 of housing 14 Perpendicular J to X-axis

Table 2 below lists five different embodiments of the stand-alone motorunit 10 of FIG. 1, which is also schematically illustrated in FIGS. 15and 16, in which the values of the distances from Table 1, inmillimeters, are provided:

TABLE 2 A B C D E F G H I J Embodiment 1 75.2-75.5 168.6 34.5 39.5 40.5115.4 66 96 115 231 Embodiment 2 75.2-75.5 175.6 34.5 39.5 40.5 139.9 6696 123 239 Embodiment 3 75.2-75.5 184.6 34.5 39.5 40.5 136.9 66 96 123253 Embodiment 4 75.2-75.5 203.1 34.5 39.5 40.5 128.4 66 96 135.3 278.3Embodiment 5 75.2-75.5 221.5 34.5 39.5 40.5 128.4 66 96 147.6 303.6

In some embodiments, dimension F, the length to the end 140 of the powertake-off shaft 38, can be modified or customized besides the dimensionslisted in Table 2.

As shown in FIG. 16, a Z-axis intersects the origin O of plane 138 andthe first and fourth sides 18, 28 of the housing 14. The Z-axis isarranged perpendicular to the X-axis and Y-axis of the plane 138. TheZ-axis is also arranged perpendicular to the first and fourth 18, 28sides of the housing 14. The Z-axis is also arranged parallel to thefifth and sixth sides 30, 32 of the housing 14. As also shown in FIG.16, a radius R5 extending from the rotational axis 122 of the powertake-off shaft 38 defines a circle 198. The rotational axis 118 of theoutput shaft 106 of the rotor 102 is intersected by the circle 198, suchthat a distance R5 is defined between the rotational axis 118 of theoutput shaft 106 and the rotational axis 122 of the power take-off shaft38. Table 3 below identifies the distances of various components andreference points with respect to the X-axis and Z-axis.

TABLE 3 Distance from Distance from X-axis Z-axis Rotational axis 118 ofoutput shaft 106 L K Rotational axis 122 of power M Intersected take-offshaft 38 by Z-axis Fourth side 28 of housing 14 N Perpendicular toZ-axis Fifth side 30 of housing 14 Perpendicular I to X-axis Sixth side32 of housing 14 Perpendicular J to X-axisTable 4 below lists the five different embodiments from Table 2 andprovides the values of the distances from Table 3, as well as R5, inmillimeters, for each embodiment:

TABLE 4 K L M N I J R5 Embodiment 1 46.9 95.3 106 329 115 231 48.1Embodiment 2 46.9 95.3 106 346 123 239 48.1 Embodiment 3 46.9 95.3 106346 123 253 48.1 Embodiment 4 46.9 95.3 106 380.6 135.3 278.3 48.1Embodiment 5 46.9 95.3 106 415.2 147.6 303.6 48.1

With continued reference to the embodiment illustrated in FIG. 16, thecontrol electronics 42 are vertically oriented relative to flange 34 andpositioned between the Z-axis and the fifth side 30 of the housing 14,while being closer to the fifth side 30 of the housing 14. As also shownin the embodiment illustrated in FIG. 16, the battery pack 50 ishorizontally oriented relative to flange 34 and positioned between therotational axis 122 of the power take-off shaft 38 and the fourth side28 of the housing 14, while being closer to the fourth side 28 of thehousing 14. However, in other embodiments, the battery pack 50 may becloser to the rotational axis 122 of the power take-off shaft 38. Thus,in all five embodiments, even when the design envelope of the housing 14of the motor unit 10 is changed, each of the battery 50, the batteryreceptacle 54, the control electronics 42, and the motor 36 fit withinthe housing 14. In some embodiments, the total weight of the motor unit10 including each of the battery 50, the battery receptacle 54, thecontrol electronics 42, and the motor 36, is 37.05 lbs. In contrast,when fully loaded with fluids, some 120 cc gas engine units can weigh upto 33.50 lbs, some 160 cc gas engine units can weigh up to 40.10 lbs,and some 200 cc gas engine units can weigh up to 41.30 lbs.

In some embodiments, the motor unit 10 includes a “kill switch” (notshown) that can be used when the motor unit 10 is coupled to, e.g., ariding lawnmower with a seat. Thus, when an operator intentionally orinadvertently gets off the seat, the kill switch discontinues power tothe motor 36 and/or control electronics 42. In some embodiments, thekill switch stops the motor 36 and/or power take-off shaft 38, butmaintains power to the power electronics 42 so that the motor unit 10may be kept in an armed or ready state. In some embodiments, the motorunit 10 requires two or more actions required to turn on the motor 36because unlike a gas engine, it may be difficult to determine whetherthe electric motor 36 is on or not. Specifically, the electric motor 36is much quieter than a gas engine. Thus, simply hitting an “on” switchmay not be enough to indicate to the operator that the motor 36 has beenturned on, because of its relative silence. Thus, by forcing theoperator to make two actions, such as holding an “on” switch and thendepressing a second actuator, the operator is made to feel more certainthat the motor 36 has been turned on.

In some embodiments, a control interface to control the power equipmentand/or the motor unit 10 is built into the motor unit 10. In someembodiments, the motor unit 10 includes a communication port and awiring harness electrically connects the motor unit 10 to the piece ofpower equipment, thus allowing the operator to control the motor unit 10from the piece of power equipment 10, or vice versa. For example, if themotor unit 10 is mounted to a lawn mower, the operator may arrange thewiring harness between the lawn mower and the communication port on themotor unit 10. The wiring harness could electrically connect a killswitch on a handlebar of the lawnmower, for example, to the motor 36 ofthe motor unit 10. Thus, if the kill switch is intentionally orinadvertently released during operation of the lawn mower, the motor 36of the motor unit 10 stops via the electrical communication through thewiring harness and communication port on the motor unit 10. Thus, thecontrol interface and communication port allow the operator flexibilityin controlling the motor unit 10 and/or the piece of power equipment.

In some embodiments, the motor unit 10 includes ON/OFF indicators (notshown). In some embodiments, the motor unit 10 includes a filter (notshown) to keep airborne debris out of the motor 36 and controlelectronics 42. In some embodiments, the filter includes a dirty filtersensor (not shown) and a self-cleaning mechanism (not shown). In someembodiments, the motor 36 will mimic a gas engine response whenencountering resistance, such as slowing down or bogging. In someembodiments, the motor unit 10 includes a heat sink 202 in the housing14 for air-cooling the control electronics 42 (FIGS. 1 and 2). In someembodiments, the motor unit 10 is liquid cooled.

In some embodiments, the output shaft 106 of the rotor 102 has bothforward and reverse capability. In some embodiments, the forward andreverse capability is controllable without shifting gears of the geartrain 110, in comparison to gas engines, which cannot achieveforward/reverse capability without extra gearing and time delay. Thus,the motor unit 10 provides increased speed, lower weight, and lowercost. Because the motor unit 10 has fewer moving parts and no combustionsystem, as compared with a gas engine, it also provides additionalspeed, weight, and cost advantages.

In some embodiments, the motor unit 10 is able to start under a “heavy”load. For example, when the motor unit 10 is mounted to a ridinglawnmower and the lawnmower is started over a patch of thick grass, themotor unit 10 is able to start the motor 36 in the thick grass. Thus,unlike gas engines, the motor unit 10 does not require a centripetalclutch. Rather, the motor 36 would always be engaged. Additionally, themotor unit 10 does not need a centrifugal clutch, in comparison to gasengines, which need a centrifugal clutch to idle and disengage from theload, or risk stalling.

The motor unit 10 is able to operate in any orientation (vertical,horizontal, upside down) with respect to a ground surface for aprolonged period of time, giving it an advantage over four-cycle gasengines, which can only be operated in one orientation and at slightinclines for a shorter period of time. Because the motor unit 10 doesnot require gas, oil, or other fluids, it can run, be transported, andbe stored upside down or on any given side without leaking or flooding

In operation, the motor unit 10 can be used to replace a gas enginesystem. Specifically, the motor unit 10 can be mounted to the piece ofpower equipment having the second bolt pattern by aligning the firstbolt pattern defined by the plurality of apertures in the flange 34 withthe second bolt pattern. Thus, the power take-off shaft 38 of the motorunit 10 can be used to drive the equipment.

During operation, the housing 14 of the motor unit 10 is comparably muchcooler than the housing of an internal combustion unit because there isno combustion in the motor unit 10. Specifically, when a gas engine unitruns, the housing of the gas engine unit is 220 degrees Celsius orhigher. In contrast, when the motor unit 10 runs, all of the exteriorsurfaces of the housing 14 are less than 95 degrees Celsius. Tables 5and 6 below list with further specificity the temperature limits ofdifferent components on the housing 14 of the motor unit 10.

Table 5 below lists the Underwriter's Laboratories (UL) temperaturelimits of different components typically used in power tools, withrespect to whether those components are formed of metal, plastic,rubber, wood, porcelain, or vitreous. The plastic rated temperatures arenever exceeded.

TABLE 5 Plastic/ Porcelain/ Metal Rubber/Wood Vitreous Casual Contact85° C. 85° C. 85° C. Handles and knobs 55° C. 75° C. 65° C. that arecontinuously held Handles and knobs 60° C. 80° C. 70° C. that are onlybriefly held (i.e. switches)

Table 6 below lists the UL temperature limits of different components ofthe battery pack housing 58 of the battery pack 50, with respect towhether those components are formed of metal, plastic or rubber. Theplastic rated temperatures are never exceeded.

TABLE 6 Metal Plastic/Rubber Casual Contact 70° C. 95° C. Handles andknobs that 55° C. 75° C. are continuously held Handles and knobs thatare 60° C. 85° C. only briefly held (i.e. switches)

FIG. 20 illustrates a simplified block diagram of the motor unit 10according to one example embodiment. As shown in FIG. 20, the motor unit10 includes an electronic processor 302, a memory 306, the battery pack50, a power switching network 310, the motor 36, a rotor position sensor314, a current sensor 318, a user input device (e.g., a trigger or powerbutton) 322, a transceiver 326, and indicators (e.g., light-emittingdiodes) 330. In some embodiments, the motor unit 10 includes fewer oradditional components than those shown in FIG. 20. For example, themotor unit 10 may include a battery pack fuel gauge, work lights,additional sensors, kill switch, the power disconnect switch 86, etc. Insome embodiments, elements of the motor unit 10 illustrated in FIG. 20including one or more of the electronic processor 302, memory 306, powerswitching network 310, rotor position sensor 314, current sensor 318,user input device (e.g., a trigger or power button) 322, transceiver326, and indicators (e.g., light-emitting diodes) 330 form at least partof the control electronics 42 shown in FIG. 3, with the electronicprocessor 302 and the memory 306 forming at least part of the controller46 shown in FIG. 3.

The memory 306 includes read only memory (ROM), random access memory(RAM), other non-transitory computer-readable media, or a combinationthereof. The electronic processor 302 is configured to communicate withthe memory 306 to store data and retrieve stored data. The electronicprocessor 302 is configured to receive instructions and data from thememory 306 and execute, among other things, the instructions. Inparticular, the electronic processor 302 executes instructions stored inthe memory 306 to perform the methods described herein.

As described above, in some embodiments, the battery pack 50 isremovably attached to the housing of the motor unit 10 such that adifferent battery pack 50 may be attached and removed to the motor unit10 to provide different amount of power to the motor unit 10. Furtherdescription of the battery pack 50 (e.g., nominal voltage, sustainedoperating discharge current, size, number of cells, operation, and thelike), as well as the motor 36 (e.g., power output, size, operation, andthe like), is provided above with respect to FIGS. 1-19.

The power switching network 310 enables the electronic processor 302 tocontrol the operation of the motor 36. Generally, when the user inputdevice 322 is depressed (or otherwise actuated), electrical current issupplied from the battery pack 50 to the motor 36, via the powerswitching network 310. When the user input device 322 is not depressed(or otherwise actuated), electrical current is not supplied from thebattery pack 50 to the motor 36. In some embodiments, the amount inwhich the user input device 322 is depressed is related to orcorresponds to a desired speed of rotation of the motor 36. In otherembodiments, the amount in which the user input device 322 is depressedis related to or corresponds to a desired torque. In other embodiments,a separate input device (e.g., slider, dial, or the like) is included onthe motor unit 10 in communication with the electronic processor 302 toprovide a desired speed of rotation or torque for the motor 36.

In response to the electronic processor 302 receiving a drive requestsignal from the user input device 322, the electronic processor 302activates the power switching network 310 to provide power to the motor36. Through the power switching network 310, the electronic processor302 controls the amount of current available to the motor 36 and therebycontrols the speed and torque output of the motor 36. The powerswitching network 310 may include numerous field-effect transistors(FETs), bipolar transistors, or other types of electrical switches. Forinstance, the power switching network 310 may include a six-FET bridgethat receives pulse-width modulated (PWM) signals from the electronicprocessor 302 to drive the motor 36.

The rotor position sensor 314 and the current sensor 318 are coupled tothe electronic processor 302 and communicate to the electronic processor302 various control signals indicative of different parameters of themotor unit 10 or the motor 36. In some embodiments, the rotor positionsensor 314 includes a Hall sensor or a plurality of Hall sensors. Inother embodiments, the rotor position sensor 314 includes a quadratureencoder attached to the motor 36. The rotor position sensor 314 outputsmotor feedback information to the electronic processor 302, such as anindication (e.g., a pulse) when a magnet of a rotor of the motor 36rotates across the face of a Hall sensor. In yet other embodiments, therotor position sensor 314 includes, for example, a voltage or a currentsensor that provides an indication of a back electro-motive force (backemf) generated in the motor coils. The electronic processor 302 maydetermine the rotor position, the rotor speed, and the rotoracceleration based on the back emf signals received from the rotorposition sensor 314, that is, the voltage or the current sensor. Therotor position sensor 314 can be combined with the current sensor 318 toform a combined current and rotor position sensor. In this example, thecombined sensor provides a current flowing to the active phase coil(s)of the motor 36 and also provides a current in one or more of theinactive phase coil(s) of the motor 36. The electronic processor 302measures the current flowing to the motor based on the current flowingto the active phase coils and measures the motor speed based on thecurrent in the inactive phase coils.

Based on the motor feedback information from the rotor position sensor314, the electronic processor 302 can determine the position, velocity,and acceleration of the rotor. In response to the motor feedbackinformation and the signals from the user input device 322, theelectronic processor 302 transmits control signals to control the powerswitching network 310 to drive the motor 36. For instance, byselectively enabling and disabling the FETs of the power switchingnetwork 310, power received from the battery pack 50 is selectivelyapplied to stator windings of the motor 36 in a cyclic manner to causerotation of the rotor of the motor 36. The motor feedback information isused by the electronic processor 302 to ensure proper timing of controlsignals to the power switching network 310 and, in some instances, toprovide closed-loop feedback to control the speed of the motor 36 to beat a desired level. For example, to drive the motor 36, using the motorpositioning information from the rotor position sensor 314, theelectronic processor 302 determines where the rotor magnets are inrelation to the stator windings and (a) energizes a next stator windingpair (or pairs) in the predetermined pattern to provide magnetic forceto the rotor magnets in a direct of desired rotation, and (b)de-energizes the previously energized stator winding pair (or pairs) toprevent application of magnetic forces on the rotor magnets that areopposite the direction of rotation of the rotor.

The current sensor 318 monitors or detects a current level of the motor36 during operation of the motor unit 10 and provides control signals tothe electronic processor 302 that are indicative of the detected currentlevel. The electronic processor 302 may use the detected current levelto control the power switching network 310 as explained in greaterdetail below.

The transceiver 326 allows for communication between the electronicprocessor 302 and an external device (for example, the user equipment338 of FIG. 21) over a wired or wireless communication network 334. Insome embodiments, the transceiver 326 may comprise separate transmittingand receiving components. In some embodiments, the transceiver 326 maycomprise a wireless adapter attached to the motor unit 10. In someembodiments, the transceiver 326 is a wireless transceiver that encodesinformation received from the electronic processor 302 into a carrierwireless signal and transmits the encoded wireless signal to the userequipment 338 over the communication network 334. The transceiver 326also decodes information from a wireless signal received from the userequipment 338 over the communication network 334 and provides thedecoded information to the electronic processor 302.

The communication network 334 provides a wired or wireless connectionbetween the motor unit 10 and the user equipment 338. The communicationnetwork 334 may comprise a short range network, for example, a BLUETOOTHnetwork, a Wi-Fi network or the like, or a long range network, forexample, the Internet, a cellular network, or the like.

As shown in FIG. 20, the indicators 330 are also coupled to theelectronic processor 302 and receive control signals from the electronicprocessor 302 to turn on and off or otherwise convey information basedon different states of the motor unit 10. The indicators 330 include,for example, one or more light-emitting diodes (“LEDs”), or a displayscreen. The indicators 330 can be configured to display conditions of,or information associated with, the motor unit 10. For example, theindicators 330 are configured to indicate measured electricalcharacteristics of the motor unit 10, the status of the motor unit 10,the mode of the motor unit 10, etc. The indicators 330 may also includeelements to convey information to a user through audible or tactileoutputs. In some embodiments, the indicators 330 include aneco-indicator that indicates an amount of power being used by the loadduring operation.

The connections shown between components of the motor unit 10 aresimplified in FIG. 20. In practice, the wiring of the motor unit 10 ismore complex, as the components of a motor unit are interconnected byseveral wires for power and control signals. For instance, each FET ofthe power switching network 310 is separately connected to theelectronic processor 302 by a control line; each FET of the powerswitching network 310 is connected to a terminal of the motor 36; thepower line from the battery pack 50 to the power switching network 310includes a positive wire and a negative/ground wire; etc. Additionally,the power wires can have a large gauge/diameter to handle increasedcurrent. Further, although not shown, additional control signal andpower lines are used to interconnect additional components of the motorunit 10.

FIG. 21 illustrates a simplified block diagram of the user equipment 338according to one example embodiment. The user equipment 338 is, forexample, a smart telephone, a tablet computer, a laptop computer, apersonal digital assistant, and the like, and may also be referred to asa personal electronic communication device. The user equipment 338allows the user to customize settings of the motor unit 10 and receiveoperation information from the motor unit 10. As shown in FIG. 20, theuser equipment 338 includes an equipment electronic processor 342, anequipment memory 346, an equipment transceiver 350, and an input/outputinterface 354. The equipment electronic processor 342, the equipmentmemory 346, the equipment transceiver 350, and the input/outputinterface 354 communicate over one or more control and/or data buses(e.g., a communication bus 358). The equipment electronic processor 342,the equipment memory 346, and the equipment transceiver 350 may beimplemented similar to the electronic processor 302, the memory 306, andthe transceiver 326 of the motor unit 10. Particularly, the equipmentelectronic processor 342 executed a motor unit application stored on theequipment memory 346 to perform functionality described herein. Theinput/output interface 354 includes one or more input components (e.g.,a keypad, a mouse, and the like), one or more output components (e.g., aspeaker, a display, and the like), or both (e.g., a touch screendisplay).

FIG. 22 illustrates a flowchart of a method 362 for no-load operation ofthe motor unit 10. In the example illustrated, the method 362 includesmeasuring, using the current sensor 318, a motor current (at block 366).The electronic processor 302 detects the current flowing through themotor using the current sensor 318 as described above. The currentsensor 318 may detect the current level at discrete time intervals, forexample, every 2 milli-seconds, and provide the control signalsindicating the current level at the discrete time intervals to theelectronic processor 302. The method 362 also includes measuring, usingthe rotor position sensor 314, the motor speed (at block 370). Theelectronic processor 302 receives feedback from the rotor positionsensor 314 when a magnet of the rotor rotates across the face of a Hallsensor. The electronic processor 302 determines the speed of the motor36 based on the frequency of the pulses received from the rotor positionsensor 314.

The method 362 further includes determining, using the electronicprocessor 302, a point on the motor power curve corresponding to themeasured motor current and the measured motor speed (at block 374). Inone example, the electronic processor 302 constructs a motor power graphhaving motor speed on the X-axis and motor current on the Y-axis. Thepoint on the motor power curve is the point corresponding to themeasured motor current and the measured motor speed on the motor powergraph.

The method 362 also includes determining, using the electronic processor302, whether the motor unit 10 is operating in a no-load condition for apre-determined period of time based on the point on the motor powercurve (at block 378). The motor 36 may be operating at full power (or100% duty cycle) or at a selected power or duty cycle corresponding tothe position of the user input device 322. The amount of current flowingto the motor 36 is proportional to the load on the motor 36. That is,when there is a high load on the motor unit 10, the motor 36 drawshigher current from the battery pack 50 and when there is a lighter loadon the motor unit 10, the motor 36 draws lower current from the batterypack 50. The electronic processor 302 determines the load on the motorunit 10 based on the point on the motor power curve. For example, for ameasured speed, the electronic processor 302 determines whether themeasured current is below a current threshold corresponding to themeasured speed. When the measured current is below the currentthreshold, the electronic processor 302 determines that the motor unit10 is operating in a no-load condition and, when the measured current isabove the current threshold, the electronic processor 302 determinesthat the motor unit 10 is not operating in a no-load condition. Theelectronic processor 302 may then further determine whether the motorunit 10 is operating in the no-load condition for the pre-determinedperiod of time. For example, the electronic processor 302 determineswhether the measured current is below the current thresholdcorresponding to the measured speed for the pre-determined period oftime.

The method 362 further includes, in response to determining that themotor unit 10 is operating in the no-load condition for a pre-determinedperiod of time, reducing, using the electronic processor 302, the motorspeed of the motor 36 to a no-load speed (at block 382). As discussedabove, the electronic processor 302 may provide control signals to thepower switching network 310 to control the speed of the motor 36 byselecting a particular pulse width modulated (PWM) duty cycle fordriving the power switching network 310. The speed control may be openloop or closed loop. The electronic processor 302 may also shutoff(i.e., reduce the duty cycle to zero) the motor when the electronicprocessor 302 determines that the motor unit 10 is operating in theno-load condition for the pre-determined period of time. In one example,the electronic processor 302 reduces the speed of the motor 36 to ano-load speed by reducing a duty cycle of the pulse width modulatedsignals provided to the power switching network 310 to 5%, 10%, or 15%.The method 362 also includes, in response to determining that the motorunit 10 is not operating in the no-load condition for the pre-determinedperiod of time, operating, using the electronic processor 302, the motor36 at a loaded speed that is greater than the no-load speed (at block386). For example, to operate at the loaded speed, the electronicprocessor 302 controls the power switching network 310 to operate themotor 36 according to the power or speed corresponding to the positionof the user input device 322 or at full power (i.e., 100% duty cycle)(for example, when the motor unit 10 does not include a variable speedtrigger). After block 382 and 386, respectively, the electronicprocessor 302 may loop back to execute block 366, thus providingcontinued load-based operation control throughout an operation of themotor unit 10.

Typical gasoline engines that drive power equipment are not controlledto reduce speed or power when the gasoline engine is operating in ano-load condition. Accordingly, gasoline engines continue to burn excessamounts of fuel and expend energy even when the gasoline engines areoperating under no-load. The electronic processor 302 executing themethod 362 detects when the motor unit 10 is operating under no-load andreduces the motor speed or power to provide additional energy savingsand then returns to normal power when loaded to meet the demand of atask. In one example, as shown in FIG. 23, by reducing the duty cycle to10% in the no-load condition, the motor unit 10 provides energy savingsof about 5 times that of a gasoline engine operating at no-load. Energysaving resulting from other reduced duty cycle levels are alsoillustrated in FIG. 23.

During operation of gas engines, an excessive input force exerted on thegas engine or a large load encountered by the power equipment powered bythe gas engine may cause a resistive force impeding further operation ofthe gas engine. For example, a gas engine encountering higher than usualloads may have its motor slowed or bogged-down because of the excessiveload. This bog-down of the motor can be sensed (e.g., felt and heard) bya user, and is a helpful indication that an excessive input, which maypotentially damage the gas engine or the power equipment, has beenencountered. In contrast, high-powered electric motor driven units,similar to the motor unit 10, for example, do not innately provide thebog-down feedback to the user. Rather, in these high-powered electricmotor driven units, excessive loading of the motor unit 10 causes themotor to draw excess current from the power source or battery pack 50.Drawing excess current from the battery pack 50 may cause quick andpotentially detrimental depletion of the battery pack 50.

Accordingly, in some embodiments, the motor unit 10 includes a simulatedbog-down feature to provide an indication to the user that excessiveloading of the motor unit 10 or power equipment is occurring duringoperation. FIG. 24 illustrates a flowchart of a method 390 for providingsimulated bog-down operation of the motor unit 10 that is similar toactual bog-down experienced by gas engines.

The method 390 includes controlling, using the electronic processor 302,the power switching network 310 to provide power to the motor 36 inresponse to determining that the user input device 322 has been actuated(at block 394). For example, the electronic processor 302 provides a PWMsignal to the FETs of the power switching network 310 to drive the motor36 in accordance with the drive request signal from the user inputdevice 322. The method 390 further includes detecting, using the currentsensor 318, a current level of the motor 36 (at block 398). Block 398,at least in some embodiments, may be performed using similar techniquesas described above for block 366 with respect to FIG. 22. The method 390also includes comparing, using the electronic processor 302, the currentlevel to a bog-down current threshold (at block 402). In response todetermining that the current level is lower than the bog-down currentthreshold, the method 390 proceeds back to block 398 such that theelectronic processor 302 repeats blocks 398 and 402 until the currentlevel is greater than the bog-down current threshold.

In response to determining that the current level is greater than thebog-down current threshold, the method 390 includes controlling, usingthe electronic processor 302, the power switching network 310 tosimulate bog-down (at block 406). In some embodiments, the electronicprocessor 302 controls the power switching network 310 to decrease thespeed of the motor 36 to a non-zero value. For example, the electronicprocessor 302 reduces a duty cycle of the PWM signal provided to theFETs of the power switching network 302. In some embodiments, thereduction in the duty cycle (i.e., the speed of the motor 36) isproportional to an amount that the current level is above the bog-downcurrent threshold (i.e., an amount of excessive load). In other words,the more excessive the load of the motor unit 10, the further the speedof the motor 36 is reduced by the electronic processor 302. For example,in some embodiments, the electronic processor 302 determines, at block406, the difference between the current level of the motor 36 and thebog-down current threshold to determine a difference value. Theelectronic processor 302 determines the amount of reduction in the dutycycle based on the difference value (e.g., by using a look-up table thatmaps the difference value to a motor speed or duty cycle).

In some embodiments, at block 406, the electronic processor 302 controlsthe power switching network 310 in a different or additional manner toprovide an indication to the user that excessive loading of the motorunit 10 is occurring during operation. In such embodiments, the behaviorof the motor 36 may provide a more noticeable indication to the userthat excessive loading of the motor unit 10 is occurring than thesimulated bog-down described above. As one example, the electronicprocessor 302 controls the power switching network 310 to oscillatebetween different motor speeds. Such motor control may be similar to agas engine-powered power equipment stalling and may provide hapticfeedback to the user to indicate that excessive loading of the motorunit 10 is occurring. In some embodiments, the electronic processor 302controls the power switching network 310 to oscillate between differentmotor speeds to provide an indication to the user that very excessiveloading of the motor unit 10 is occurring. For example, the electronicprocessor 302 controls the power switching network 310 to oscillatebetween different motor speeds in response to determining that thecurrent level of the motor 36 is greater than a second bog-down currentthreshold that is greater than the bog-down current threshold describedabove with respect to simulated bog-down. As another example, theelectronic processor 302 controls the power switching network 310 tooscillate between different motor speeds in response to determining thatthe current level of the motor 36 has been greater than the bog-downcurrent threshold described above with respect to simulated bog-down fora predetermined time period (e.g., two seconds). In other words, theelectronic processor 302 may control the power switching network 310 tosimulate bog-down when excessive loading of the motor unit 10 isdetected and may control the power switching network 310 to simulatestalling when excessive loading is prolonged or increases beyond asecond bog-down current threshold.

With respect to any of the embodiments described above with respect toblock 406, other characteristics of the motor unit 10 and the motor 36may provide indications to the user that excessive loading of the motorunit 10 is occurring (e.g., tool vibration, resonant sound of a shaft ofthe motor 36, and sound of the motor 36). In some embodiments, thesecharacteristics change as the electronic processor 302 controls thepower switching network 310 to simulate bog-down or to oscillate betweendifferent motor speeds as described above.

The method 390 further includes detecting, using the electronicprocessor 302, the current level of the motor 36 (at block 410). Themethod 390 also includes comparing, using the electronic processor 302,the current level of the motor 36 to the bog-down current threshold (atblock 414). When the current level remains above the bog-down currentthreshold, the method 362 proceeds back to block 402 such that theelectronic processor 302 repeats blocks 402 through 414 until thecurrent level decreases below the bog-down current threshold. In otherwords, the electronic processor 302 continues to simulate bog-down untilthe current level decreases below the bog-down current threshold.Repetition of blocks 402 through 414 allows the electronic processor 302to simulate bog-down differently as the current level changes butremains above the bog-down current threshold (e.g., as mentionedpreviously regarding proportional adjustment of the duty cycle of thePWM provided to the FETs).

When the current level of the motor 36 decreases below the bog-downcurrent threshold (e.g., in response to the user reducing the load onthe motor unit 10), the method 390 includes controlling, using theelectronic processor 302, the power switching network 310 to ceasesimulating bog-down and operate in accordance with the actuation of theuser input device 322 (i.e., in accordance with the drive request signalfrom the user input device 322) (at block 416). In other words, theelectronic processor 302 controls the power switching network 310 toincrease the speed of the motor 36 from the reduced simulated bog-downspeed to a speed corresponding to the drive request signal from the userinput device 322. For example, the electronic processor 302 increasesthe duty cycle of the PWM signal provided to the FETs of the powerswitching network 310. In some embodiments, the electronic processor 302gradually ramps the speed of the motor 36 up from the reduced simulatedbog-down speed to the speed corresponding to the drive request signalfrom the user input device 322. Then, the method 390 proceeds back toblock 394 to allow the electronic processor 302 to continue to monitorthe motor unit 10 for excessive load conditions. In some embodiments ofthe method 390, in block 414, a second current threshold different thanthe bog-down threshold of block 402 is used. For example, in someembodiments, the bog-down threshold is greater than the second currentthreshold.

FIG. 25 illustrates a schematic control diagram of the motor unit 10that shows how the electronic processor 302 implements the method 390according to one example embodiment. The electronic processor 302receives numerous inputs, makes determinations based on the inputs, andcontrols the power switching network 310 based on the inputs anddeterminations. As shown in FIG. 25, the electronic processor 302receives a drive request signal 418 from the user input device 322 asexplained previously herein. In some embodiments, the motor unit 10includes a slew rate limiter 422 to condition the drive request signal418 before the drive request signal 418 is provided to the electronicprocessor 302. The drive request signal 418 corresponds to a first drivespeed of the motor 36 (i.e., a desired speed of the motor 36 based on anamount of depression of the user input device 322 or based on thesetting of a secondary input device). In some embodiments, the driverequest signal 418 is a desired duty ratio (e.g., a value between0-100%) of the PWM signal for controlling the power switching network310.

The electronic processor 302 also receives a motor unit current limit426 and a battery pack current available limit 430. The motor unitcurrent limit 426 is a predetermined current limit that is, for example,stored in and obtained from the memory 306. The motor unit current limit426 indicates a maximum current level that can be drawn by the motorunit 10 from the battery pack 50. In some embodiments, the motor unitcurrent limit 426 is stored in the memory 306 during manufacturing ofthe motor unit 10. The battery pack current available limit 430 is acurrent limit provided by the battery pack 50 to the electronicprocessor 302. The battery pack current available limit 430 indicates amaximum current that the battery pack 50 is capable of providing to themotor unit 10. In some embodiments, the battery pack current availablelimit 430 changes during operation of the motor unit 10. For example, asthe battery pack 50 becomes depleted, the maximum current that thebattery pack 50 is capable of providing decreases, and accordingly, asdoes the battery pack current available limit 430. The battery packcurrent available limit 430 may also be different depending on thetemperature of the battery pack 50 and/or the type of battery pack 50.Although the limits 426 and 430 are described as maximum current levelsfor the motor unit 10 and battery pack 50, in some embodiments, theseare firmware-coded suggested maximums or rated values that are, inpractice, lower than true maximum levels of these devices.

As indicated by floor select block 434 in FIG. 25, the electronicprocessor 302 compares the motor unit current limit 426 and the batterypack current available limit 430 and determines a lower limit 438 usingthe lower of the two signals 426 and 430. In other words, the electronicprocessor 302 implementing a function, floor select 434, determineswhich of the two signals 426 and 430 is lower, and then uses that lowersignal as the lower limit 438. The electronic processor 302 alsoreceives a detected current level of the motor 36 from the currentsensor 318. At node 442 of the schematic diagram, the electronicprocessor 302 determines an error (i.e., a difference) 446 between thedetected current level of the motor 36 and the lower limit 438. Theelectronic processor 302 then applies a proportional gain to the error446 to generate a proportional component 450. The electronic processor302 also calculates an integral of the error 446 to generate an integralcomponent 454. At node 458, the electronic processor 302 combines theproportional component 450 and the integral component 454 to generate acurrent limit signal 462. The current limit signal 462 corresponds to adrive speed of the motor 36 (i.e., a second drive speed) that is basedon the detected current level of the motor 36 and one of the motor unitcurrent limit 426 and the battery pack current available limit 430(whichever of the two limits 426 and 430 is lower). In some embodiments,the current limit signal 462 is in the form of a duty ratio (e.g., avalue between 0-100%) for the PWM signal for controlling the powerswitching network 310.

As indicated by floor select block 466 in FIG. 25, the electronicprocessor 302 compares the current limit signal 462 and the driverequest signal 418 and determines a target PWM signal 470 using thelower of the two signals 462 and 418. In other words, the electronicprocessor 302 determines which of the first drive speed of the motor 36corresponding to the drive request signal 418 and the second drive speedof the motor 36 corresponding to the current limit signal 462 is less.The electronic processor 302 then uses the signal 418 or 462corresponding to the lowest drive speed of the motor 36 to generate thetarget PWM signal 470.

The electronic processor 302 also receives a measured rotational speedof the motor 36, for example, from the rotor position sensor 314. Atnode 474 of the schematic diagram, the electronic processor 302determines an error (i.e., a difference) 478 between the measured speedof the motor 36 and a speed corresponding to the target PWM signal 470.The electronic processor 302 then applies a proportional gain to theerror 478 to generate a proportional component 482. The electronicprocessor 302 also calculates an integral of the error 478 to generatean integral component 486. At node 490, the electronic processor 302combines the proportional component 482 and the integral component 486to generate an adjusted PWM signal 494 that is provided to the powerswitching network 310 to control the speed of the motor 36. Thecomponents of the schematic diagram implemented by the electronicprocessor 302 as explained above allow the electronic processor 302 toprovide simulated bog-down operation of the motor unit 10 that issimilar to actual bog-down experienced by gas engines. In other words,in some embodiments, by adjusting the PWM signal 494 in accordance withthe schematic control diagram, the motor unit 10 lowers and raises themotor speed in accordance with the load on the motor unit 10, which isperceived by the user audibly and tactilely, to thereby simulate bogdown. FIGS. 25 and 26 illustrate a closed loop speed control of themotor 36. In some embodiments, the method 390 uses open loop speedcontrol of the motor 36. For example, in FIGS. 25 and 26, the method 390can be adapted for open loop speed control by eliminating node 474, theproportional component 482, the integral component 486, the node 490,and the feedback signal from the rotor positions sensor 314.

FIG. 26 illustrates a schematic control diagram of the motor unit 10that shows how the electronic processor 302 implements the method 390according to another example embodiment. The control process illustratedin FIG. 26 is similar to the control process illustrated in FIG. 25.However, rather than determining the lower limit 438 based on the motorunit current limit 426 and the battery pack current available limit 430,the electronic processor 302 determines the lower limit 438 based on aninput received from the user equipment 338. For example, the user maydefine the motor performance on the user equipment 338 by providingcurrent, power, torque, or performance parameters (referred to as motorperformance parameters) over the input/output interface of the userequipment 338. The user equipment 338 communicates the motor performanceparameters defined by the user to the electronic processor 302 over thecommunication network 334. The electronic processor 302 determines thelower limit 438 based on the motor performance parameters. For example,the electronic processor 302 uses the current defined in the motorperformance parameters as the lower limit 438. The control process shownin FIG. 26 provides the user the ability to customize performance of themotor unit 10 according to the needs of the power equipment.

In some embodiments, the motor performance parameters may be definedbased on an application of the motor unit 10. The motor unit 10 may beused to power different kinds of power equipment for differentapplications. The user may select the application that the motor unit 10is being used for on the input/output interface 354 of the userequipment 338. The equipment electronic processor 342 may determine themotor performance parameters based on the application selected by theuser. For example, the equipment electronic processor 342 may refer to alook-up table in the equipment memory 346 mapping each application ofthe motor unit 10 to a set of motor performance parameters. Theequipment electronic processor 342 may then provide the motorperformance parameters to the electronic processor 302. In someembodiments, the user equipment 338 may provide the application selectedby the user to the electronic processor 302. The electronic processor302, rather than the equipment electronic processor 338, may determinethe motor performance parameters based on the application selected bythe user. For example, the electronic processor 302 may refer a look-uptable in the memory 306 mapping each application of the motor unit 10 toa set of motor performance parameters.

In some embodiments, the electronic processor 302 may perform a systemcompatibility check prior to each power-up to determine whether themotor unit 10 is capable of the power outputs defined by the user. FIG.27 is a flowchart of a method 498 for system compatibility checkaccording to one example embodiment. As shown in FIG. 27, the method 498includes receiving, via the transceiver 326, a load command from theuser equipment 338 (at block 502). For example, the electronic processor302 receives the motor performance parameters from the equipmentelectronic processor 342 as described above. The motor performanceparameters may include an output power requirement (i.e., the loadcommand) of the motor unit 10. In some embodiments, the load command isa rotation speed of the motor unit 10 (e.g., 5000 RPM). For example, theuser may select the rotation speed or an application that maps to therotation speed on the user equipment 338. The electronic processor 302determines the amount of load or current draw required to operate themotor at the selected speed (i.e., the load command). The method 498also includes determining, using the electronic processor 302, a loadlimit of the battery pack 50 (at block 506). The electronic processor302 determines the load limit based on, for example, battery type,battery state of charge, battery age, and the like. In some embodiments,the electronic processor 302 determines the load limit based on thebattery pack current available limit 430. In some embodiments, the loadlimit is a maximum speed that can be attained based on the batteryconditions. For example, the electronic processor may determine that themaximum rotational speed that can be achieved based on the poweravailable through the battery pack 50 is 4000 RPM.

The method 498 further includes determining, using the electronicprocessor 302, whether the load command exceeds the load limit (at block510). The electronic processor 302 compares the load command to the loadlimit to determine whether the load command exceeds the load limit. Inresponse to determining that the load command does not exceed the loadlimit, the method 498 includes performing, using the electronicprocessor 302, normal operation of the motor unit 10 (at block 514).Performing normal operation of the motor unit 10 includes controllingthe power switching network 310 to operate the motor 36 according to theload command provided by the user and the input from the user inputdevice 322. For example, the electronic processor 302 provides a PWMsignal to the FETs of the power switching network 310 to drive the motor36 in accordance with the drive request signal from the user inputdevice 322. In response to determining that the load command exceeds theload limit, the method 498 includes performing, using the electronicprocessor 302, limited operation of the motor unit 10 (at block 518).Performing limited operation may include for example, turning off themotor 36, running the motor 36 with limited power within the load limitof the battery pack 50, or the like. In one example, performing limitedoperation may include simulating bog-down of the motor unit 10 asdescribed above. In some embodiments, the electronic processor 302 mayalso warn the user that the load command exceeds the load limit. Forexample, the electronic processor 302 may provide an indication to theuser equipment 338 that the load command exceeds the load limit. Theuser equipment 338 in response to receiving the indication from theelectronic processor 302 provides an audible, tactile, or visualfeedback to the user indicating that the load command exceeds the loadlimit. For example, the user equipment 338 displays a warning text onthe input/output interface 354 that the load command exceeds the loadlimit. In some embodiments, the electronic processor 302 activates theindicators 330 to warn the user that the load command exceeds the loadlimit. The user may then adjust the load command based on the warningreceived from the electronic processor 302. After block 514 and 518,respectively, the electronic processor 302 loops back to the block 502.

FIG. 28 illustrates a pump system 520 including a frame 524 supportingthe stand-alone motor unit 10 and a pump 528 with the motor unit 10operable to drive the pump 528. The illustrated pump 528 is acentrifugal pump having an impeller positioned within a housing 532 ofthe pump 528 that is rotatable about an axis to move material from aninlet 536 of the pump 528 to an outlet 540 of the pump 528.Specifically, the pump 528 is a “trash pump” that includes enoughclearance between the impeller of the pump 528 and the housing 532(e.g., 8 millimeters) to provide a mixture of a liquid (e.g., water) anddebris (e.g., solid material like mud, small rocks, leases, sand,sludge, etc.) to pass through the pump 528 from the inlet 536 to theoutlet 540 without the debris getting trapped within the pump 528 anddecreasing the performance of the pump system 520. The pump system 520driven by the motor unit 10 includes many advantages over a conventionalpump driven by an internal combustion engine, some of which arediscussed below.

The motor unit 10 of the pump system 520:

-   -   drives the pump 528 in two different directions to clear the        pump 528 if debris is stuck within the pump 528 (without        utilizing a transmission including a forward gear and a rearward        gear);    -   is operable by AC power (e.g., from a standard 120 volt outlet)        or DC power (e.g., from a battery pack) to drive the pump 528 to        eliminate a downtime refueling period of the internal combustion        engine;    -   eliminates an air intake and an exhaust outlet such that the        motor unit 10 can be fluidly sealed in a water proof housing;    -   is operable in a wider speed range than a comparable internal        combustion engine, for example, the motor unit 10 is operable at        a lower speed range (e.g., less than 2,000 revolutions per        minute) than a comparable internal combustion engine to increase        runtime of the motor unit 10, and the motor unit 10 is also        operable at a higher speed range (e.g., greater than 3,600        revolutions per minute) than a comparable internal combustion        engine to provide a broader output capability;    -   operates the pump 528 regardless of the orientation of the motor        unit 10, unlike an internal combustion engine that can only can        operate in one orientation (e.g., an upright orientation); and    -   eliminates fuel and oil to operate—unlike an internal combustion        engine—allowing the pump system 520 to run, be transported, or        stored at any orientation (e.g., upside down or on its side)        without the motor unit 10 leaking oil or flooding with fuel.

In addition, the electronic processor 302 of the motor unit 10 can, forexample:

-   -   via first sensors 541 in the pump 528 that are in communication        with the electronic processor 302, detect an amount of liquid        being moved through the pump 528 to enable operation of the pump        528 if the amount of liquid is at or above a threshold level and        automatically stops operation of the pump 528 if the amount of        liquid is below the threshold level. However, in other        embodiments, the electronic processor 302 can simply monitor the        current drawn by the motor 36 to determine whether to slow down        or stop the motor 36;    -   provide a battery status that at least represents a power level        of the battery pack of the motor unit 10;    -   be in communication with a remote control to start or stop the        motor unit 10 remotely with the remote control including status        indicators of the motor unit 10;    -   turn ON/OFF the motor unit 10—and ultimately the pump 528,        change a speed of the motor unit 10, change a flow rate of        liquid and debris exiting the outlet 540, provide a timer (e.g.,        automatically turn OFF the motor unit 10), provide a delayed        start of the motor unit 10—all of which can occur without direct        user input (e.g., via sensors or programs);    -   be in communication with other power tools to provide        tool-to-tool communication and coordination;    -   be in communication with a wireless network to track the        location of the pump system 520, report the pump system 520        usage and performance data, disable/enable the pump system 520        remotely, change the performance of the pump system 520        remotely, etc.;    -   be in communication with digital controls on a customizable user        interface (e.g., a touch display) that control, regulate,        measure different aspects of the motor unit 10 and/or the pump        528;    -   via second sensors 542 on the pump 528 that are in communication        with the electronic processor 302 and arranged in an impeller        reservoir, monitor suction or fluid level in the impeller        reservoir and signal that the pump 528 is not adequately primed        or automatically shut off the pump 528 to protect the pump        system 520;    -   electronically control a valve 543 on the pump 528 to adjust an        exhaust opening to support an auto-priming capability;    -   electronically control the valve 543 to adjust the exhaust        opening so that only air exits and slowly reopen the valve 543        until suction is established;    -   adjust pressure or flow rate of the pump 528 with the speed of        the motor unit 10 instead of a throttle; and    -   control a priming mode or “soft start” that optimizes the speed        of the impeller of the pump 528 for self-priming, and governing        to a slower speed until full suction is achieved.

Test specifications of the pump system 520 appear in Table 7 below:

TABLE 7 Full Speed Low Speed Motor Speed (RPM) 19,627 7,452 AverageCurrent (Amperes) 38.0 2.11 Peak Current (95%) (Amperes) 43 2Instantaneous Peak Current (Amperes) 46 43 Average Voltage (V) 69.976.41 Average Power (HP) 3.56 0.22 Peak Power (95%) (HP) 4.16 0.23Runtime (Minutes) 9.20 96.86 Flow Rate (Gallons per Minute) 120.3 48.9Total Pumped (Gallons) 1,098 4,753

The values listed in Table 7 were measured during a full discharge cycleof the battery pack 50 (i.e., full charge to shutoff due to the voltageof the battery pack 50 dropping below a predetermined value).

FIG. 29 illustrates a jetter 544 including a frame 545 with a pair ofwheels 546 and a handle 548. The frame 545 supports the stand-alonemotor unit 10 and a pump 550 driven by the motor unit 10. The pump 550includes an inlet 551 that receives fluid from an inlet line 552connected to a fluid source 553 (e.g. a spigot or reservoir). The pump550 also includes an outlet 554 from which an outlet line 556 extends.The frame 545 supports a hose reel 558 that supports a hose 559 that isfluidly coupled to the outlet line 556 and includes a jetter nozzle 560.The hose 559 and jetter nozzle 560 are fluidly coupled with the pump 550via the outlet line 556, such that the pump 550 pumps fluid from thefluid source 553 to the jetter nozzle 560. The jetter nozzle 560includes back jets 564 and one or more front jets 568.

In operation, the motor unit 10 drives the pump 550, which supplieswater or another fluid from the fluid source 553 to the nozzle 560, suchthat the back jets 564 of the jetter nozzle 560 propel the jetter nozzle560 and 559 hose through a plumbing line while front jets 568 of thenozzle 560 are directed forward to break apart clogs in the plumbingline, blasting through sludge, soap, and grease. Once propelled asufficient distance through the plumbing line, an operator may use thehose reel 558 to retract the hose 559 and jetter nozzle 560 back throughthe plumbing line, while the pump 550 continues to supply fluid to theback and front jets 564, 568 to break up debris in the line and flushdebris therethrough. The jetter 544 including the motor unit 10possesses advantages over a conventional jetter with an internalcombustion engine, some of which are discussed below. For instance, themotor unit 10 can be pulsed to clear a jam in the plumbing line.

In addition, the electronic processor 302 of the motor unit 10 can, forexample:

-   -   Communicate with fluid level sensors 572 on the pump 550 to        detect whether an adequate level of fluid is available;    -   Communicate with inlet and outlet sensors 573, 574 respectively        located at the inlet and outlet lines 552, 556 to prevent the        motor unit 10 from being activated until the inlet and outlet        lines 552, 556 for the pump 550 are sufficiently bled of air;    -   adjust pressure or flow rate of the pump 550 with the speed of        the motor unit 10 instead of a throttle or regulator; and    -   turn ON/OFF the motor unit 10—and ultimately the pump 550,        change a speed of the motor unit 10, change a flow rate of        liquid through the pump 550, provide a timer (e.g.,        automatically turn OFF the motor unit 10), provide a delayed        start of the motor unit 10—all of which can occur without direct        user input (e.g., via sensors or programs).

Test specifications of the jetter 544 appear in Table 8 below:

TABLE 8 Full Speed Motor Speed (RPM) 17,773 Average Current (Amperes)55.7 Peak Current (95%) (Amperes) 64 Instantaneous Peak Current(Amperes) 67 Average Voltage (V) 65.4 Average Power (HP) 5.29 Peak Power(95%) (HP) 6.18 Runtime (Minutes) 5.7 Peak Jet Pressure (PSI) 2070

The values listed in Table 8 were measured during a full discharge cycleof the battery pack 50 (i.e., full charge to shutoff due to the voltageof the battery pack 50 dropping below a predetermined value).

FIG. 30 illustrates a compactor 576 including a frame 580 supporting thestand-alone motor unit 10, a vibrating plate 584, and a vibrationmechanism 588 intermediate the motor unit 10 and vibrating plate 584,such that the motor unit 10 can drive the vibration mechanism 588 todrive the vibrating plate 584. The frame 580 includes a handle 592 andalso supports a water tank 596 with a valve 600 through which water orother liquid can be applied to the surface to be compacted or thevibrating plate 584. In some embodiments, the compactor 576 includes apaint sprayer 604 to spray and demarcate lines or boundaries in andaround the compacting operation.

In operation, an operator can grasp the handle 592 and activate themotor unit 10 to drive the vibrating plate 584 to compact soil orasphalt, including granular, mixed materials that are mostlynon-cohesive. During operation, the operator may control the valve 600to allow water from the water tank 596 to be applied to the compactedsurface, such that in some applications, the water allows the compactedparticles to create a paste and bond together, forming a denser ortighter finished surface. In addition, the water from the water tank 596prevents asphalt or other material from adhering to the vibrating plate584 during operation.

The compactor 576 can be used in parking lots and on highway or bridgeconstruction. In particular, the compactor 576 can be used inconstruction areas next to structures, curbs and abutments. Thecompactor 576 can also be used for landscaping for subbase and pavercompaction. The compactor 576 including the motor unit 10 possessesadvantages over a conventional compactor with by an internal combustionengine, some of which are discussed below. For instance, the motor 36 ofthe motor unit 10 can run forward or reverse, allowing the operator toshift directional bias of the vibration mechanism 588. Thus thevibration mechanism 588 is configured to move or “walk” itself forwardor reverse, depending on how the operator has shifted the directionalbias of the vibration mechanism 588.

In addition, the electronic processor 302 of the motor unit 10 can, forexample:

-   -   sense the levelness of compaction, such as the grade or pitch,        by communicating with an auxiliary sensor device such as a        surveying and grading tool 608;    -   sense the degree of compactness, such as whether the material        being compacted is loose or sufficiently tight, by communicating        with an auxiliary or onboard device 610 such as a durometer        probe, ultrasound, accelerometer, or gyroscope. However, in        other embodiments, the electronic processor 302 can simply        monitor the current drawn by the motor 36 to sense the level of        compactness;    -   turn ON/OFF the motor unit 10—and ultimately the vibration        mechanism 588, change a speed of the motor unit 10, and output        direction and steering of the compactor system 576;    -   use sensors 611 on the compactor system 576 that are in        communication with the electronic processor 302 to detect where        a compacted surface dips and in response, control the paint        sprayer 604 to mark where more material is needed at the        detected dip; and    -   control the valve 600 of the water tank 596 to adjust the flow        rate to the vibrating plate or compacted surface.

Test specifications of the compactor 576 appear in Table 9 below:

TABLE 9 Full Speed Motor Speed (RPM) 19,663 Average Current (Amperes)26.4 Peak Current (95%) (Amperes) 32 Instantaneous Peak Current(Amperes) 52 Average Voltage (V) 71.9 Average Power (HP) 2.55 Peak Power(95%) (HP) 3.24 Runtime (Minutes) 12.78

The values listed in Table 9 were measured during a full discharge cycleof the battery pack 50 (i.e., full charge to shutoff due to the voltageof the battery pack 50 dropping below a predetermined value).

In another embodiment of a compactor 576 shown schematically in FIG. 31,the vibration mechanism 588 is a multi-motor drive system with fourseparate vibration mechanisms 588 a, 588 b, 588 c, 588 d, each havingits own motor and each configured to respectively vibrate an individualquadrant 612, 614, 616, 618 of the vibrating plate 584. Each vibrationmechanism 588 a, 588 b, 588 c, 588 d, is controlled by a controller 620of the compactor 576. Thus, depending on readings from the auxiliary oronboard sensor devices 608, 610 described above, the controller 620 canselect which quadrant 612, 614, 616, 618 requires vibration. In someembodiments, the controller 620 may receive instructions from anoperator via, e.g., a remote control. In some embodiments, thecontroller 620 can control the vibration mechanisms 588 a, 588 b, 588 c,588 d to move the compactor 576 forward or reverse, as well as steer orturn the compactor 576 via the vibration plate 584.

FIG. 32 illustrates a rammer 624 including a body 628 supporting thestand-alone motor unit 10, a vibrating plate 632, and a vibrationmechanism 636 intermediate the motor 10 and vibrating plate 632, suchthat the motor unit 10 can drive the vibration mechanism 636 to drivethe vibrating plate 632. The rammer 624 includes a handle 640 extendingfrom the body 628 to enable an operator to manipulate the rammer 624.

In operation, an operator can grasp the handle 640 and activate themotor unit 10 to drive the vibrating plate 632 to compact cohesive andmixed soils in compact areas, such as trenches, foundations andfootings. The rammer 624 including the motor unit 10 possessesadvantages over a conventional rammer driven with an internal combustionengine, some of which are discussed below.

For instance, the electronic processor 302 of the motor unit 10 can, forexample:

-   -   turn ON/OFF the motor unit 10—and ultimately the vibration        mechanism 636, change a speed of the motor unit 10;    -   provide a delayed start of the motor unit 10—all of which can        occur without direct user input (e.g., via sensors or programs);        and    -   utilize preset modes for compacting soft, hard, loose, or tight        material.

The electronic processor 302 can also input data from sensors 642 on therammer 624 to detect whether the frequency and/or amplitude of thevibrating plate is within a predetermined range, such that the controlelectronics 42 can precisely control the speed of the motor unit 10 andadjust the frequency of vibration of the vibration mechanism 636. Inthis manner, the electronic processor 302 can prevent amplifiedvibration or resonance and ensure that the rammer 624 is under controlwhen the operator wishes to lower the output speed and reduce the rateof compaction. Also, this ensures that vibration energy is beingefficiently transferred into the surface material instead of theoperator.

Test specifications of the rammer 624 appear in Table 10 below:

TABLE 10 Full Speed Motor Speed (RPM) 19,863 Average Current (Amperes)19.7 Peak Current (95%) (Amperes) 28 Instantaneous Peak Current(Amperes) 56 Average Voltage (V) 72.7 Average Power (HP) 1.92 Peak Power(95%) (HP) 2.76 Runtime (Minutes) 15.73

The values listed in Table 10 were measured during a full dischargecycle of the battery pack 50 (i.e., full charge to shutoff due to thevoltage of the battery pack 50 dropping below a predetermined value).

As shown in FIG. 33, in some embodiments, the gear train 110 of themotor unit 10 includes a terminal male shaft section 644 to which afirst female shaft subassembly 648 can mount within a gearbox 650 of themotor unit 10. The first female shaft subassembly 648 includes a firstpower take-off shaft 38 a configured to drive a first tool and a femalesocket 652 that mates with the male shaft section 644. In the embodimentof FIG. 33, a second female shaft subassembly 656 is provided with thefemale socket 652 and a second power take-off shaft 38 b configured todrive a second tool that is different than the first tool. Thus, thefirst and second female shaft subassemblies 648, 656 may be convenientlyswapped in and out of mating relationship with the male shaft section644 to allow an operator to quickly and conveniently adapt the motorunit 10 to drive different first and second tools. In contrast, atypical gas engine does not permit such quick or convenient replacementof the power take-off shaft.

As shown in FIG. 34, in some embodiments, the gear train 110 of themotor unit 10 includes a terminal female shaft section 660 to which afirst male shaft subassembly 664 can mount within the gearbox 650 of themotor unit 10. The first male shaft subassembly 664 includes the firstpower take-off shaft 38 a configured to drive the first tool and a maleshaft section 668 that mates with the female shaft section 660. In theembodiment of FIG. 34, a second male shaft subassembly 672 is providedwith the male shaft section 668 and the second power take-off shaft 38 bconfigured to drive the second tool. Thus, the first and second maleshaft subassemblies 664, 672 may be conveniently swapped in and out ofmating relationship with the female shaft section 660 to allow anoperator to quickly and conveniently adapt the motor unit 10 to drivedifferent first and second tools. In contrast, a typical gas engine doesnot permit such quick or convenient replacement of the power take-offshaft. In some embodiments, the male shaft section 668 mates with thefemale shaft section 660 via a splined connection. In the embodimentillustrated in FIG. 34, the first and second male shaft subassemblies664, 672 are axially retained to the gearbox 650 via a retaining ring673 on the gearbox 650.

In some embodiments, the female socket 652 mates with the male shaftsection 644, and the male shaft section 668 mates with the female shaftsection 660, via any of the following connection methods: spline-fit(FIG. 34), keyed, half-circle shaft w/ female bore (FIG. 35), tongue &groove (FIG. 36), double “D” (FIG. 37), face ratchet bolted together,Morse taper, internal/external thread, pinned together, flats and setscrews, tapered shafts, or serrated connections (FIG. 38).

In some embodiments, different types of power take-off shaftsubassemblies 38 may couple to the gear train 110 using a quick-connectstructure similar to any of the following applications: modular drill,pneumatic quick connect, socket set-style, ball-detent hex coupling,drill chuck, pins filling gaps around shaft, hole saw arbor. In someembodiments, different types of power take-off shaft subassemblies 38may couple to the gear train 110 using one of the following couplingstructures: Spring coupling, c-clamp style, love joy style, platesw/male/female pegs (FIG. 39), or female collar with radial fasteners(FIG. 40).

In another embodiment shown in FIG. 41, the geartrain 110 includes afemale shaft section 674 with a gear 674 a and an elongate bore 675 forreceiving a stem 676 a of a first male shaft subassembly 676 having thefirst power take-off shaft 38 a. The female shaft section 674 isrotatably supported in the gearbox 650 by first and second bearings 677,678. Once received in the elongate bore 675, the first male shaftsubassembly 676 is axially secured to the female shaft section 674 via afastener 679 inserted into the stem 676 a of the first male shaftsubassembly 676 a while securing a washer 680 between the fastener 679and the stem 676 a of the first male shaft subassembly 676. Thus, unlikethe embodiments of FIGS. 33 and 34, the embodiment of FIG. 41 requiresthe operator to access a side 681 of the gearbox 650 opposite thefaceplate 124 to access the fastener 679. In the embodiment of FIG. 41,a second male shaft subassembly having the second power take-off shaft38 b can be inserted in lieu of the first male shaft subassembly 676 toallow an operator to conveniently adapt the motor unit 10 to drivedifferent first and second tools. In contrast, a typical gas engine doesnot permit such quick or convenient replacement of the power take-offshaft.

In an embodiment shown in FIG. 43, a shaft subassembly 682 may beremovably coupled to the gearbox 650. Specifically, the shaftsubassembly 682 includes the faceplate 124, the power take-off shaft 38rotatably supported by a first bearing 688 in the faceplate 124, and afirst gear 692 arranged on and coupled for rotation with the powertake-off shaft 38. In some embodiments, the power take-off shaft 38 isaxially constrained with respect to the faceplate 124 with a retainingring 694. The shaft subassembly 682 is removably received in a recess696 of the gearbox 650. The recess 696 includes a second bearing 700 forrotatably supporting an end 704 of the power take-off shaft 38 withinthe recess 696 when the shaft subassembly 682 is received in the recess696 and coupled to the gearbox 650.

Also, when the shaft subassembly 682 is received in the recess 696 andcoupled to the gearbox 650, the faceplate 124 covers the gear train 110and the first gear 692 is the final gear of the gear train 110, suchthat the gear train 110 can drive the power take-off shaft 38 using afirst overall reduction ratio. When the shaft subassembly 682 is removedfrom the gearbox 650, the first gear 692 can be replaced with a secondgear. Using the second gear with the shaft subassembly 682 results in asecond overall reduction ratio of the gear train 110. The second overallreduction ratio is different than the first overall reduction ratio,such that an operator can reconfigure the shaft subassembly 682 fordriving different tools by swapping between the first gear 692 and thesecond gear. Also, when the shaft subassembly 682 is removed from thegearbox 650, at least a portion of the gear train 110 is exposed, thusenabling an operator to replace, repair, or access certain gears withinthe gear train 110.

As shown in FIG. 43, the motor 36 mounts to a portion of the gearbox 650that has a generally C-shaped cross-section, and the faceplate 124 ispart of a shaft subassembly 682 including the power take-off shaft 38,with the faceplate 124 being generally planar. In an alternativeembodiment shown in FIG. 44, the geometries are swapped from those ofthe embodiment of FIG. 43. Specifically, the motor 36 mounts to aportion of the gearbox 650 having a generally planar cross-section andthe faceplate 124 has a generally reverse-C-shaped cross-section.

As shown in FIG. 45, in some embodiments, a first gearbox 650 a with afirst gear train 110 a is removably attachable to an adapter plate 712adjacent the motor 36 in the housing 14, such that the output shaft 106of the motor 36 can drive the first gear train 110 a when the firstgearbox 650 a is attached to the adapter plate 712. A second gearbox 650b with a second gear train 110 b that has a different reduction ratiothan the first gear train 110 a is also removably attachable to theadapter plate 712. Thus, depending on what tool an operator wishes todrive with the motor unit 10, an operator can select either the first orsecond gearboxes 650 a, 650 b. In some embodiments, the first and secondgearboxes 650 a, 650 b can attach to the adapter plate 712 via a bayonetconnection. In some embodiments, there are a plurality of additionalgearboxes respectively having different gear trains than the first andsecond gear trains 110 a, 110 b, each of the additional gearboxes beingattachable to the adapter plate 712.

Instead of swappable gearboxes 650 a, 650 b as in the embodiment of FIG.45, and instead of embodiments of FIGS. 19 and 43 that allow an operatorto change or replace individual gears, in some embodiments the geartrain 110 in the gearbox 650 includes a transmission allowing anoperator to shift gear sets to change the reduction ratio. In someembodiments, the gear train 110 in the gearbox 650 has a predeterminednumber of stages that can be arranged in different combinations toproduce different outputs. For example, as shown in FIG. 46, the gearbox650 might include three slots 716, 720, 724 for acceptingcartridge-style gear stages 728, 732, 736, 740, 744 (e.g., planetarystages). Thus, depending on the output that an operator desires from thegear train 110, the operator can selectively insert three of the fivestages 728, 732, 736, 740, 744 into the three slots 716, 720, 724 in aparticular order depending on which tool the operator wishes the motorunit 10 to drive.

As shown in FIG. 47, in some embodiments, the motor 36 is envelopedwithin the gear train 110 in the gearbox 650. Specifically, the outputshaft 106 of the motor 36 acts as a sun gear with three planetary gears748, 752, 756 between the output shaft 106 and a ring gear 760 thatincludes a first face gear 764. First and second spur gear 768, 772 arearranged between the first face gear 764 and a second face gear 776.

As shown in FIG. 48, in some embodiments, the flange 34 is configured totranslate all or part of the housing 14 and gearbox 650 with respect tothe flange 34 to provide freedom for varying geometries of the powertake-off shaft 38. For instance, the flange 34 may include a groove 777for receipt of a tongue 778 of the housing or gearbox 650 to permitlateral translation. In some embodiments, a locking mechanism 779 may beincluded to lock the housing 14 at a particular position with respect tothe flange 34. The lateral translation of housing 14 with respect toflange 34 permits an operator to slide the housing 14 in a directionaway from the tool to which the motor unit 10 is mounted, then serviceor remove the power take-off shaft 38, without having to decouple theflange 34 from the tool. In some embodiments, the housing 14 cantranslate with respect to the flange 34 in a direction parallel to,perpendicular to, or both parallel and perpendicular to the rotationalaxis 122 of the power take-off shaft 38.

As shown in FIG. 49, in some embodiments, the power take-off shaft 38 iscoupled to an input shaft 780 of a tool via an endless drive member 784(e.g., a belt or chain) that is coupled to first and second pulleys 785,786 that are respectively arranged on the power take-off shaft 38 andinput shaft 780. In the embodiment of FIG. 49, the motor unit 10 alsoincludes a tensioner 788 with a spring 792 to adjust the tension of theendless drive member 784. In some embodiments, the first pulley 785 canbe arranged on the input shaft 780 and the second pulley 786 can bearranged on the power take-off shaft 38 to produce a different gearreduction ratio.

As shown in FIG. 50, in some embodiments, the gearbox 650 is sectionedto have a quartile faceplate 124 that allows for access to only thepower take-off shaft 38.

As shown in FIG. 51, in some embodiments, the battery 50 can be storedwithin a cover 796 to protect the electronics from the ingress of wateror moisture. In some embodiments, the cover 796 is a hard case cover796. As shown in FIG. 52, in some embodiments, the battery 50 includes asystem lock out apparatus, such as a keypad 797 or a key, which can beutilized to prevent unauthorized individuals from accessing the battery50, for example, in a scenario in which the battery 50 has been rentedalong with the motor unit 10.

Because the control electronics 42 of the motor unit 10 don't requireintake of ambient air for combustion or exhaust of noxious gases, thecontrol electronics 42 can be fully sealed within a fully sealedwaterproof compartment within housing 14. As shown in FIG. 42a , in someembodiments, the housing 14 includes doors 798 that can open and closeat various locations on the housing 14 to allow an operator to quicklyreconfigure where the air intake and exhaust ports are located forcooling of the motor 36. In some embodiments, the motor unit 10 canoperate using AC power from a remote power source, or DC power via thebattery 50. Additionally, the motor unit 10 may include an AC poweroutput 799, as a passthrough or inverted to AC power, for connectionwith an AC power cord of a power tool. In some embodiments, the housing14 includes inlets 801 (FIG. 42a ) for pressurized air for cleaning orto supplement a cooling airflow.

In some embodiments, the motor unit 10 can be mated with a new tool(e.g. one of the pump system 520, jetter 544, compactor 576, or rammer624) and the memory 306 can be reprogrammed to optimize the motor unit10 for operation with the new tool. In some embodiments, the electronicprocessor 302 automatically recognizes which type of new tool the motorunit 10 has been mated with, and governs operation of the motor unit 10accordingly. In some embodiments, the electronic processor 302 canautomatically detect with which tool the motor unit 10 has been matedvia Radio Frequency Identification (RFID) communication with the newtool.

In some embodiments, the memory 306 is reprogrammable via eitherBLUETOOTH or Wi-Fi communication protocols. In some embodiments, theelectronic processor 302 has control modes for different uses of thesame tool. The control modes may be preset or user-programmable, and maybe programmed remotely via BLUETOOTH or Wi-Fi. In some embodiments, theelectronic processor 302 utilizes master/slave tool-to-toolcommunication and coordination, such that the motor unit 10 can exertunidirectional control over a tool, or an operator can use a smartphoneapplication to exert unidirectional control over the motor unit 10.

In some embodiments, the operator or original equipment manufacturer(OEM) is allowed limited access to control the speed of the motor unit10 through the electronic processor 302 via, e.g., a controller areanetwork (CAN)-like interface. In some embodiments, the electronicprocessor 302 is capable of a wider range of speed selection with asingle gear set in the gear train 110 than a gasoline engine. Forexample, the control electronics 42 are configured to drive the motor 36at less than 2,000 RPM, which is lower than any speed a gasoline engineis capable of, which permits the associated tool to have a greateroverall runtime over a full discharge of the battery 50, than a gasolineengine. Additionally the control electronics 42 are configured to drivethe motor at more than 3,600 RPM, which is higher than any speed agasoline engine is capable of, and with the capability to deliver moretorque. The wider range of speeds of motor 36 offers greater efficiencyand capability than a gasoline engine. In some embodiments, the operatorcould have access to control the current drawn by the motor 36 inaddition to the speed.

In some embodiments, the electronic processor 302 is configured to logand report data. For example, the electronic processor 302 is configuredto provide wired or wireless diagnostics for monitoring and reading thestatus of the motor unit 10. For example, the electronic processor 302can monitor and log motor unit 10 runtime for example, in a rentalscenario. In some embodiments, the motor 36 and the electronic processor302 use regenerative braking to charge the battery 50. In someembodiments, the motor unit 10 includes a DC output 803 for lights oraccessories (FIG. 42). In some embodiments, the electronic processor 302can detect anomalies or malfunctions of the motor unit 10 via voltage,current, motion, speed, and/or thermocouples. In some embodiments, theelectronic processor 302 can detect unintended use of or stoppage of themotor unit 10. If the tool driven by the motor unit 10 (e.g. one of thepump system 520, jetter 544, compactor 576, or rammer 624) is notrunning with the intended characteristics or is not being used correctlyor safely, the electronic processor 302 can detect the anomaly anddeactivate the motor unit 10. For example, the motor unit 10 can includeone or more accelerometers to sense if the motor unit 10 and tool is inthe intended orientation. And, if the electronic processor 302determines that the motor unit 10 is not in the intended orientation(i.e. the tool has fallen over), the electronic processor 302 candeactivate the motor unit 10.

In some embodiments, the motor unit 10 includes accessible sensor ports802 (FIG. 42) to electrically connect with user-selected sensors for usewith the piece of power equipment, such as accelerometers, gyroscopes,GPS units, or real time clocks, allowing an operator to customize thevariables to be sensed and detected by the electronic processor 302. Insome embodiments, the electronic processor 302 can indicate the statusof the battery 50, such as when the battery is running low, to anoperator via visual, audio, or tactile notifications. In someembodiments, the electronic processor 302 can operate an auxiliary motorthat is separate from the motor 36 to drive an auxiliary device such asa winch. The auxiliary motor may be internal or external to the motorunit 10.

In some embodiments, the motor unit 10 can include digital controls on acustomizable user interface, such as a touch display or a combination ofknobs and buttons. In contrast, an analog gasoline engine does notinclude such digital controls. In some embodiments, the user interfacefor the motor unit 10 can be modular, wired, or wireless and can beattachable to the motor unit 10 or be hand held. In some embodiments,the motor unit 10 can be controlled with a remote control 804 thatincludes status indicators for certain characteristics of the motor unit10, such as charge of the battery 50 and the temperature, as shown inFIG. 53. In some embodiments, the motor unit 10 can provide statusindications with a remote, programmable device. In some embodiments, theremote control 804 can include a USB cord 808 that plugs into a USB port812 on the battery 50 (FIG. 52), or a USB port elsewhere on the motorunit 10, such that the remote control 804 can be charged by the battery50. In some embodiments the remote control 804 can be charged wirelesslyfrom the battery 50. The remote control 804 can include a variety ofcontrols, such as:

a button 816 to turn the motor unit 10 on or off;

a joystick 820 to steer the tool (e.g., the compactor 576);

a dial 824 to adjust the flow rate of the tool (e.g. the pump system 520or jetter 544);

a timer 828 for a delayed start or stop of the tool; and

a switch 832 to select forward or reverse directions of the powertake-off shaft 38.

The remote control 804 can also control the operating pressure of thetool (e.g. the pump system 520 or jetter 544), or other operatingcharacteristics of the tool.

Various features of the invention are set forth in the following claims.

1. A stand-alone motor unit for use with a piece of power equipment, themotor unit comprising: a housing; a flange coupled to the housing on afirst side thereof; a plurality of apertures through the flange defininga first bolt pattern that matches an identical, second bolt patterndefined in the piece of power equipment; an electric motor locatedwithin the housing and having a power output of at least about 2760 Wand a nominal outer diameter of up to about 80 mm, the motor including astator, and a rotor supported for relative to the stator, a powertake-off shaft receiving torque from the rotor and protruding from oneof the flange or a second side of the housing adjacent the first side; acontroller positioned within the housing and electrically connected tothe motor; a battery pack including a pack housing, battery cellssupported by the pack housing, the battery cells being electricallyconnected and having a nominal voltage of up to about 80 V, and a firstterminal electrically connected to the battery cells; and a batteryreceptacle coupled to the housing and including a second terminalelectrically connected to the controller and engageable with the firstterminal to transfer current between the battery pack and the motor. 2.The stand-alone motor unit of claim 1, wherein the motor includes abrushless direct current motor.
 3. The stand-alone motor unit of claim1, wherein the battery pack is connectable to and supportable by thebattery receptacle such that the battery pack is supportable by thehousing of the stand-alone motor unit.
 4. The stand-alone motor unit ofclaim 1, wherein each of the battery cells has a diameter of up to about21 mm and a length of up to about 71 mm.
 5. The stand-alone motor unitof claim 1, wherein the battery pack includes up to 20 battery cells. 6.The stand-alone motor unit of claim 1, wherein the battery cells areconnected in series.
 7. The stand-alone motor unit of claim 1, whereinthe battery cells are operable to output a sustained operating dischargecurrent of between about 40 A and about 60 A.
 8. The stand-alone motorunit of claim 1, wherein each of the battery cells has a capacity ofbetween about 3.0 Ah and about 5.0 Ah.
 9. The stand-alone motor unit ofclaim 1, further comprising control electronics including thecontroller, the control electronics having a volume of up to about 920mm³, and wherein the motor has a volume of up to about 443,619 mm³. 10.The stand-alone motor unit of claim 1, further comprising controlelectronics including the controller, the control electronics having aweight of up to about 830 g, and wherein the motor has a weight of up toabout 4.6 lb., and the battery pack has a weight of up to about 6 lb.11. The stand-alone motor unit of claim 1, wherein the rotor includes anoutput shaft, and wherein the stand-alone motor unit further comprises agear train transferring torque from the output shaft to the powertake-off shaft.
 12. The stand-alone motor unit of claim 11, wherein thegear train includes a planetary transmission.
 13. The stand-alone motorunit of claim 12, wherein a rotational axis of the output shaft iscoaxial with a rotational axis of the power take-off shaft.
 14. Thestand-alone motor unit of claim 12, wherein the output shaft includes apinion configured as a sun gear of the planetary transmission, andwherein the planetary transmission further includes a ring gear and aplurality of planet gears between the sun gear and the ring gear. 15.The stand-alone motor unit of claim 14, wherein the ring gear includes afirst face gear and the gear train further includes a second face gearand one or more spur gears arranged between the first face gear and thesecond face gear.
 16. The stand-alone motor unit of claim 15, whereinthe motor is at least partially arranged between the first and secondface gears.
 17. The stand-alone motor unit of claim 16, wherein arotational axis of the output shaft is coaxial with the first and secondface gears.
 18. The stand-alone motor unit of claim 11, wherein the geartrain includes a spur gear engaged with the output shaft.
 19. Thestand-alone motor unit of claim 18, wherein a rotational axis of theoutput shaft is parallel with a rotational axis of the power take-offshaft.
 20. The stand-alone motor unit of claim 11, wherein the geartrain includes a bevel gear engaged with the output shaft.
 21. Thestand-alone motor unit of claim 20, wherein a rotational axis of theoutput shaft is perpendicular to a rotational axis of the power take-offshaft.
 22. The stand-alone motor unit of claim 21, wherein therotational axis of the output shaft intersects the second side of thehousing and the power take-off shaft protrudes from the flange.
 23. Thestand-alone motor unit of claim 1, wherein the controller is configuredto determine whether the stand-alone motor unit is operating in ano-load condition for a pre-determined period of time, in response todetermining that the stand-alone motor unit is operating in the no-loadcondition, reduce the motor speed of the motor to a no-load speed, andin response to determining that the stand-alone motor unit is notoperating in the no-load condition, operating the motor at a loadedspeed that is greater than the no-load speed.
 24. The stand-alone motorunit of claim 23, wherein the controller determines whether thestand-alone motor unit is operating in the no-load condition based ondetecting a motor current.
 25. The stand-alone motor unit of claim 23,wherein the controller determines whether the stand-alone motor unit isoperating in the no-load condition based on detecting a motor speed. 26.The stand-alone motor unit of claim 23, wherein the controllerdetermines whether the stand-alone motor unit is operating in theno-load condition for the pre-determined period of time based ondetermining a point of the stand-alone motor unit on a motor powercurve.
 27. The stand-alone motor unit of claim 1, further comprising: acurrent sensor, the controller electrically connected to the currentsensor, wherein the controller is configured to: measure, using thecurrent sensor, a motor current, measure a motor speed, determine apoint on a motor power curve corresponding to the measured motor currentand the measured motor speed, determine whether the stand-alone motorunit is operating in a no-load condition for a pre-determined period oftime based on the point on the motor power curve, in response todetermining that the stand-alone motor unit is operating in the no-loadcondition for a pre-determined period of time, reduce the motor speed ofthe motor to a no-load speed, and in response to determining that thestand-alone motor unit is not operating in the no-load condition for apre-determined period of time, operating the motor at a loaded speedthat is greater than the no-load speed.
 28. The stand-alone motor unitof claim 1, further comprising: a user input device electricallyconnected to the controller; a current sensor electrically connected tothe controller; and a power switching network electrically connectedbetween the controller and the motor, wherein the controller isconfigured to: control the power switching network to provide power tothe motor in response to determining that the user input device has beenactuated, detect, using the current sensor, a current level of themotor, compare the current level to a bog-down current threshold, and inresponse to determining that the current level is greater than thebog-down current threshold, control the power switching network tosimulate bog-down.
 29. The stand-alone motor unit of claim 28, whereinsimulating bog-down includes at least one selected from the groupconsisting of controlling the power switching network to decrease thespeed of the motor to a non-zero value, reducing the duty cycle of thepower switching network proportional to an amount that the current levelis above the bog-down current threshold, and controlling the powerswitching network to oscillate between different motor speeds.
 30. Thestand-alone motor unit of claim 28, after simulating bog-down, thecontroller is further configured to: detect a second current level ofthe motor compare the second current level to the bog-down currentthreshold, and in response to the second current level decreasing belowthe bog-down current threshold, control the power switching network tocease simulating bog-down and operate the motor in accordance withactuations of the user input device.
 31. The stand-alone motor unit ofclaim 1, further comprising a transceiver electrically connected to thecontroller, wherein the controller is configured to: receive, via thetransceiver, a load command from the piece of power equipment, determinea load limit of the battery pack, determine whether the load commandexceeds the load limit, in response to determining that the load commanddoes not exceed the load limit, perform normal operation of thestand-alone motor unit, in response to determining that the load commandexceeds the load limit perform limited operation of the stand-alonemotor unit.
 32. The stand-alone motor unit of claim 31, wherein normaloperation of the stand-alone motor unit includes controlling the powerswitching network to operate the motor according to the load command.33. The stand-alone motor unit of claim 31, wherein limited operation ofthe stand-alone motor unit includes operating the motor with limitedpower within the load limit of the battery pack.
 34. The stand-alonemotor unit of claim 31, wherein limited operation of the stand-alonemotor unit includes simulating bog-down. 35.-195. (canceled)